Preheat your oven to 350°F (175°C) and grease three 8-inch round cake pans, dusting with flour.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt.

In a large bowl, beat softened butter and sugar until pale and fluffy. Add eggs one at a time, mixing well after each.

Incorporate vanilla and almond extracts into the butter mixture.

Gradually add dry ingredients and buttermilk to the butter mixture, starting and ending with the dry ingredients. Gently fold in cherry puree.

Divide the batter into the prepared pans and bake for 25-30 minutes until a toothpick inserted in the center comes out clean. Let cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

For the blackberry filling, combine blackberries, sugar, and lemon juice in a saucepan over medium heat. Cook for about 5 minutes until berries soften.

Stir in the cornstarch-water mixture and cook until thickened (2-3 minutes). Let cool completely.

For the cherry buttercream frosting, beat softened butter until creamy, gradually adding powdered sugar and cherry puree until smooth. Mix in vanilla extract and salt.

Assemble the cake by layering one cake on a plate, adding blackberry filling, then the second layer, repeating until all layers are stacked. Frost the top and sides with cherry buttercream, garnishing with fresh cherries and blackberries.