Preheat oven to 350F.  Mix the coffee granules with the boiling water.  In a separate bowl, sift together the flour, sugar, cocoa, baking powder and soda, and salt.

In another bowl, combine the buttermilk, eggs, oil, vanilla and coffee.  Add the wet ingredients to the dry, and mix until combined.  Grease two 8inch cake pans, dusting with cocoa powder to prevent sticking, then pour the batter equally into both pans.  Bake for 1 hour. Remove from pans and allow to cool fully.

Whisk the flour, sugar and salt together in a pot.  Add the milk and whisk till combined, then place over a burner on low heat.  Allow mixture to come to a boil, whisking constantly. Once boiling, cook for 1-2 minutes until thickened.  Remove from heat and immediately stir in the white chocolate, whisking until fully dissolved and incorporated.

Using a spatula, scrape onto a large flat plate. Cover with saran wrap to prevent a skin from forming, and allow to cool.

Once pudding has cooled to room temperature, beat the butter until light and fluffy, around 5-6 minutes.  Now add 1 tbsp of pudding to the butter, beating it in after each addition.  Once the pudding is all added, mix in the vanilla extract.  Smush the buttercream against the sides of the bowl with a spatula, to remove any large bubbles.

Use immediately or store in the fridge for 1 week.  Allow to come to room temperature before using from the fridge and mix with beaters until smooth again.  Can also be frozen for up to 2 months.

Place cake in fridge to harden slightly for 20 minutes. Remove from fridge and using a long serrated knife, cut the dome off the cakes so you have a flat surface. Spin the cake as you cut so that you can keep an eye on the knife being level. Using the same method, you will then cut both layers in two, so you can make a four layer cake.

Start layering the cake.  Use jam for the bottom layer, the middle layer will be frosting and the top layer is jam again.  Using a cake spatula, put a thin layer of icing on the cake as a "crumb coat", then put in the fridge or somewhere cold for 20 minutes.  Once the icing has hardened, you can frosting the rest of the cake.  Enjoy!