Pre-heat oven to 335F (conventional) and prepare 3 8" cake pans with parchment paper and butter / oil

Make sure the butter, eggs and buttermilk are at room temp. The butter should be soft but not melting

Add the flour (sifted), sugar, baking powder, baking soda and salt to the bowl of your stand mixer and mix together. Add the butter. Whisk on medium speed for ~1-2 minutes until the mixture resembles coarse sand / crumbs. Make sure to scrape the bowl to ensure everything is well combined

Separately, whisk together the eggs, buttermilk, oil, vanilla and almond extract until the eggs are broken down

Add a third of the wet ingredients to the dry ingredients and whisk on medium speed until combined. Scrape the bowl, and add the remaining wet ingredients. Whisk on medium speed until combined. Scrape the bowl again

Now increase the speed to medium-high and whisk for 2 minutes. You should have a light and fluffy cake batter

Divide the batter evenly between the cake pans and bake for ~28-30 minutes until the cakes are light golden and a toothpick inserted in the middle comes out with a few moist crumbs attached (no sticky batter)

Let the cakes cool down in the pans for 20 minutes, then very carefully remove them and place on a wire rack. Place in the fridge for 30 minutes so the cakes can thoroughly cool down (if chilling for longer, wrap the cakes in cling wrap)

Add the water, sugar and jam to a saucepan and mix

Heat on low flame until the mixture starts to simmer and sugar has dissolved. This should not be a thick syrup

Set aside to cool down

Add the mascarpone cheese, sugar and vanilla to a bowl and whisk on low speed for 30-60 seconds until the mixture looks creamy. Do not overmix

Separately, whisk the heavy cream for a few minutes until it reaches firm peaks. Do not overmix

Add the whipped cream to the mascarpone mixture in 2 additions, gently folding it in until combined. You should have a thick and fluffy frosting

Roughly chop the berries if you haven't already

Place a cake layer onto a turntable. ideally with a cake round underneath

Use a sharp serrated knife to remove a thin layer of the cake crust on top to expose the crumb

Use a pastry brush to generously brush on the berry simple syrup. Do not soak too much as the cake will become saturated and break otherwise

Spread on a thin layer of the chantilly frosting

Spread on the berries evenly, leaving ~½" empty from the edges of the cake

Add more chantilly frosting and spread it, pressing down slightly to fill the gaps between the berries. Add more frosting on the edges of the cake to ensure they're covered. Use frosting generously!

Repeat with the next layer of cake

For the last cake layer, trim off the crust and brush with syrup before putting onto the turntable. Then flip upside down and layer on top of the cake you are assembling (so the side brushed with syrup is facing down and the side with the crust is facing up)

Apply a thin layer of frosting all over the cake as evenly as you can. This is the crumb coating

Refrigerate for 15-20 minutes, then add the remaining frosting generously all over the cake

Decorate with any remaining frosting and berries

If you need to transfer the cake to a serving stand, let it chill for an hour first so the frosting can firm up

Serve and enjoy!