Making the Lemon Berry Mascarpone Cake is a straightforward process. Follow these steps to create a delicious masterpiece:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Mix Dry Ingredients: In a large bowl, sift together the flour, baking powder, and salt.
3. Cream Butter and Sugar: In another bowl, cream the softened butter and granulated sugar until light and fluffy.
4. Add Eggs and Flavorings: Beat in the eggs, one at a time, followed by the lemon juice, lemon zest, and vanilla extract until well combined.
5. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, alternating with the milk. Mix until smooth and well blended.
6. Divide Batter: Pour the batter evenly into the prepared cake pans.
7. Bake: Place the pans in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
8. Cool Cakes: Remove the cakes from the oven and allow them to cool in the pans for 10 minutes. Then, transfer the cakes to wire racks to cool completely.
9. Prepare Mascarpone Filling: In a bowl, beat the mascarpone cheese until smooth and creamy. You can add a little powdered sugar for sweetness if desired.
10. Assemble the Cake: Once the cakes are completely cooled, place one layer on a serving platter. Spread a layer of mascarpone filling over the top, followed by a generous layer of mixed berries. Place the second cake layer on top.
11. Frost the Top: Spread the remaining mascarpone filling on top of the second layer. Decorate with additional berries.
12. Dust with Powdered Sugar: For an elegant finish, dust the top with powdered sugar before serving.

By following these steps, you will create a stunning Lemon Berry Mascarpone Cake that is sure to impress!