Chocolate chip and passion fruit cake truffles and birthday cake truffles

Chocolate chip and passion fruit or Birthday cake truffles! Glutenfree or not, using up leftover sponge cake… and two Christina Tosi layer cakes! :)

Special everyday cakes and treats

There are loads of reasons for making cake truffles:  it’s great to recycle leftover sponge languishing in the freezer; a lumbersome birthday cake can be transformed into portable energy balls for the great outdoors or bar hopping; its fun making something super easy with kids; and finally they’re really yummy!  All you do is crumble sponge with your hands, add a little liquid like milk, fruit juice or purée then knead together to make little balls.  What makes me prefer these to cake pops is there isn’t a thick layer of chocolate around the truffles and there’s no battle making balls stay on sticks!  These truffles are based on Christina Tosi’s – her layer of chocolate is super thin then covered in ‘sand’, aka very fine cookie crumbs.  My leftover sponge and crumbs are gluten-free, originally made for her two milk bar creations: the Birthday layer cake and Chocolate chip layer cake.  These cakes are delightfully buttery, sweet, salty and delicious so the recipe links are also included.  The truffles themselves were tested by several participants under diverse conditions (tee hee):  after rock-climbing, at the end of a cava night and during a live music concert.  These little power balls of flavour amazed everyone and one friend immediately pre-ordered a birthday selection box!  Even one or two balls will make a perfect dessert and keep you going for hours!  Some preferred the Passion fruit and chocolate truffles with that zingy punch of fruit and others really enjoyed the Birthday truffles with that wonderful balance of vanilla and milk.  I’d have to try some again to check which I like best… lol.  At some point it will be fun experimenting with different sponges and flavours to make more cake truffles!  Perhaps you’d like to get cake truffling too?

Cake truffles

Cake truffles

The Christina Tosi inspiration

I watched Christina Tosi in the Chef Table’s fourth Pastry series on Netflix and like many others loved seeing her child-like enthusiasm for amazing cakes where you can see the frosting layers.  So I got her Milk Bar book and have really enjoyed it.  They’re quirky fun cakes to make, look at and eat.  Yes these American-style cakes and truffles are buttery and quite sweet but surprisingly not too much:  they’re balanced with a lovely amount of salt and the overall flavours and textures are amazing.  Tosi has a background in pâtisserie, which shows through her effective inventive techniques and combinations.  She also makes the processes easier and more relaxing with no piping or trying to smooth perfect frosting.  So if you’ve ever experienced layer cake or cake pop despair…

cake pop despair

… these cake truffles are for you (and me). 😉



I used Doves Farm self-raising gluten free flour for the sponges and crumbs (‘crumbs’ are like unformed cookies here).  For the birthday cake crumb I also replaced the granulated sugar with maple syrup and increased the amount of flour then generally used a little less vanilla flavouring, replacing some of the clear artificial extract with pure vanilla extract.  I know Tosi’s idea for the birthday cake is to recreate the artificial taste of box cakes but my Wilton’s extract had a chemical after-taste so it needed a bit of pure stuff.


The layer cake recipes are in the Momofoku milk bar book.  Or follow the links below to the online recipes then read my notes for extra tips and adaptations.  Wouldn’t you love some of these cakes or truffles?

Milk bar layer cake and truffles assortment

Equipment notes

Baking tin I used:  32cm x 23cm (13in x 9in) and 4.5 to 5cm high (2in) – more or less similar to this rectangular tin.

Note:  for the layer cake I used a 14cm/5.5in diametre cake ring (4.5cm/1.7in high) to cut out 2 whole layers and the third layer is made up of 2 halves.  I then stuck two lengths of acetate strip (6cm/2.4in wide) together horizontally, to make an acetate strip 12cm wide and lined the cake ring with it.  Do adapt according to the size of your cake ring and acetate strip.  The remaining sponge can be used for the truffles

Ingredient notes

  • Use medium-large eggs (about 53-55g) and add about 10g/ml extra buttermilk if using glutenfree flour mix.
  • For the birthday cake Christina Tosi recommends McCormick clear artificial vanilla extract (less chemical after taste apparently) – or if you can’t get hold of it use a little less Wilton’s like me, combined with pure vanilla extract.
  • It feels wrong to use Criscos vegetable fat but it works really well and the frosting’s delicious (will try finding a healthier substitute one day).
  • Use good-quality decent sized rainbow sprinkles so they’re not too small and don’t lose their colour.
  • For the chocolate chip cake Tosi recommends mini chocolate chips (Barry callebaut).

Method notes

  • whisking up the sponge batter on the standmixer can take longer than stated in the original recipe and even if it doesn’t go extra fluffy or double in size it still seems to work.


Milk bar birthday layer cake

Online recipe link:  Birthday Cake on milk bar website (cups and grammes);

My healthier Birthday cake crumb adaptation (gluten free and less sweet)

  • 25g (2 tbsp) light brown sugar
  • 80g (4 tbsp) pure maple syrup
  • 150 – 170g glutenfree flour mix (put a little less then check the consistency and add more if needed)
  • 2g/1/2 tsp baking powder
  • 2g/1/2 tsp sea salt
  • 5g/1 tsp clear vanilla extract and 5g/1 tsp pure vanilla extract
  • 40g/2tbsp grapeseed oil (or light olive oil)
  • 20g/2 tbsp rainbow sprinkles

It takes a while to bake – longer than in the original recipe.

(Only use about 2/3 of it for the cake and keep the remaining third for the truffles sand)

Birthday cake frosting adaptation – use 1/4-1/2 teaspoon fresh lemon juice instead of the citric acid and 4 – 5g clear vanilla extract plus 4 – 5g pure vanilla extract (to taste).

CHOCOLATE CHIP LAYER CAKE (with passionfruit curd and coffee frosting)

Milk bar chocolate chip layer cake

Online recipe linksChocolate chip layer cake – ABC (in cups/ounces) or Margaret in the City’s post (cups and grammes), and for detailed photos and tips (but not the ingredient list) go to Cooking by the Book’s post.

Chocolate chip sponge

Coffee frosting adaptations:  some online bakers double the quantities to make enough for the layers but I managed with 1 and 1/2 times the quantity.

  • 172g/3/4 cup or 1.5 stick unsalted butter
  • 60g/1/2 cup less 3/4 tsp icing/powdered sugar
  • 82g/ml full-fat milk
  • 1 + 1/8 tsp (2.2g) instant coffee powder (Nescafé)
  • 1/4 + 1/8 tsp (1.5g) fine sea salt

Chocolate crumb adaptations:  make a gluten-free lower-sugar version as for the Birthday Cake crumb adaptation above.  If making the original recipe watch carefully when baking after the first 5 minutes as it burns quickly and needs less than 20 minutes..

The cake truffles

Chocolate chip and passion fruit cake truffles or birthday cake truffles?

Chocolate chip and passion fruit and birthday cake truffles

Online recipe linkB’day Truffles on milk bar website.

The truffles can be made with two elements from the layer cakes:  the sponge and the Birthday Cake crumb/Chocolate crumb.  Or make the Birthday Sand in the milk bar B’day Truffles recipe.  Alternatively use a buttery fairly dense sponge and ‘sand’ made by processing cookies of your choice.

For about 12 truffles (23-25g/rounded tbsp each)

The quantities are approximate – it’s flexible, depending on taste and how dense or moist your sponge is.

  • 250g – 275g cake sponge – more or less the quantity left over after making the layer cake
  • 1 tbsp or more liquid (for the birthday truffles:  milk plus a little vanilla; for the chocolate chip truffles:  fresh passion fruit purée or juice – could maybe add a few drops of milk or vanilla to the passion fruit to mellow it)
  • 30g/1oz or more good-quality white chocolate (like Valrhona), for a very thin layer
  • 55g/1/3 to 1/2 cup ‘sand’ made by grinding the Birthday Cake/Chocolate Crumb or make the Birthday Sand (alternatives: grind graham crackers/digestive biscuits, Lotus speculoos or Oreo cookies).  For the chocolate chip truffles I mixed chocolate crumb with birthday cake crumb.

Cake truffles

Eating and storing

Store in an airtight container in the fridge up to a week or freeze up to 1 month.  Just eat 1 or 2 in one sitting! 🙂  And you can take them climbing!

Climbing with cake truffles

So there you go, some very yummy cake truffles and layer cakes.  If you want to experience amazing American-style treats do go for it and make yourself and a lot of other people happy.  As happy as Christina Tosi eating cake.

Here are some birthday cake truffles for you!  And Chocolate chip and passion fruit cake truffles!  One of each?  Someone’s already had a nibble…! 😉

Cake truffles

Chocolate chip and passion fruit or Birthday cake truffles?

Well bye again dear reader!  May your week be sweet and yummy!  Happy baking, no-baking and eating! 🙂 Lili x

Posted by

Baking on Sundays with my French mum was a lovely part of my childhood. Later I experimented with baking books or internet recipes and did the pâtisserie course at Le Cordon Bleu Paris. Still trying out new recipes and inventing cakes with influences from all around the world, including some healthier ones. Yes, love cakes!!! Hope you'll love them too and have fun baking. :)

4 thoughts on “Chocolate chip and passion fruit or Birthday cake truffles! Glutenfree or not, using up leftover sponge cake… and two Christina Tosi layer cakes! :)”

    • I can understand why, how nice you get to drink her milk shakes – all the stuff in Tosi’s Milk Bar book looks addictive! 🙂

      Liked by 1 person

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