1. Preheat the oven to 350°F (180°C). Grease a heart baking pan lightly and set aside. You can also use a heart-shaped baking frame – place that one on a baking sheet lined with baking parchment and set aside.

 

2. Working with just one large bowl add the flour, brown sugar, cocoa powder, espresso powder, baking powder, baking soda, and salt to the bowl and mix until well combined. Add the eggs, vanilla extract, oil, and milk and mix until combined. Add the hot water and mix everything until well combined. Pour the batter into the prepared baking tin or baking frame and bake for 30-35 minutes or until a wooden skewer inserted into the center comes out clean. Take out of the oven and let cool for some time in the baking pan, then remove and let cool down completely on a wire rack.

 

3. For the berry filling wash and dry the berries. If you use frozen ones, let them defrost. Try to save all the juices. Add the sugar and cornstarch to a small bowl and mix. Add water, lemon juice, and vanilla extract to a pot and mix. Add the cornstarch-sugar mixture and whisk until there are no more lumps. Bring the mixture to a boil, then add the berries and let simmer for 2-4 minutes – the berries should be soft but not mushy and the liquids should have thickened. Take off the heat and let cool down completely.

 

4. For the buttercream add the egg whites and sugar to a large heatproof bowl and place on a pot with simmering water. Mix slowly until the temperature of the mixture reaches a temperature of 160°F (71°C) and the sugar has dissolved completely. Take off the heat and mix with a kitchen machine or handheld mixer for about 5 minutes on high speed until the egg whites are glossy and stiff peaks form. The bowl should have room temperature. Add the soft butter in small pieces – one after another and mix in well each time. Add the vanilla extract and confectioners‘ sugar and mix first slowly, then on high speed for about 5 minutes until thick and creamy. Divide the buttercream into several portions and mix with the food colors you like. Fill into piping bags with different piping tips – make one piping bag with a large round tip with uncolored buttercream and set aside.

 

5. To assemble the cake cut the cake in half and place the bottom part on a serving plate. Use the uncolored buttercream and pipe little dollops/swirls along the edge of the cake layer to create a barrier for the filling – you should have one continuous barrier or else the filling will come through. Add the berries filling on top and distribute evenly up to the buttercream barrier. Place the second cake layer on top and press down a bit. Place in the fridge for about 10-15 Minutes.

 

6. Use the colored buttercream to pipe roses, swirls, and dots onto the cake. Sprinkle with some sugar sprinkles. Store in the fridge and let get back to room temperature before serving.