Almond Layer Cake with Blackberry Buttercream for 12

Instructions:

1. Place blackberries in a small saucepan over medium heat. Mash the berries as they soften and release juices.
2. Pass the blackberry mixture through a fine-mesh sieve into a clean bowl to remove seeds. Discard seeds and return the juice to the saucepan.
3. Simmer the blackberry juice until it reduces to a thick, concentrated syrup. Set aside to cool completely.
4. Preheat oven to 175°C (350°F). Grease and line three 8-inch round cake pans with parchment paper.
5. In a large bowl, whisk together the all-purpose flour, almond flour, baking powder, and sea salt.
6. In a stand mixer fitted with the paddle attachment, cream 225g butter and granulated sugar until light and fluffy.
7. Gradually add egg whites, almond extract, and vanilla bean paste, mixing until fully incorporated.
8. In another jug, mix the 240ml milk and 120g sour cream. Add the dry and wet ingredients to the butter mixture in three additions, starting and ending with the dry.
9. Divide batter evenly between the prepared pans and bake for 30-35 minutes or until a tester comes out clean.
10. For the buttercream, beat 450g of slightly chilled butter until it is velvety and pale. Gradually add powdered sugar, lemon juice, and 30-45ml of your cooled blackberry reduction. Whip on high for 3 minutes until it looks like purple clouds. Add heavy cream only if needed for consistency.
11. Once cakes are completely cooled, frost between layers and around the exterior of the cake.