Creating a stunning Berry Cake is simple when you follow these clear steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
2. Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, and salt until well combined. Set aside.
3. Cream Butter and Sugar: In a large mixing bowl, cream the softened butter and granulated sugar together until light and fluffy.
4. Add Eggs and Vanilla: Beat in the eggs one at a time, mixing well after each addition. Then, add the vanilla extract and mix until combined.
5. Combine Mixtures: Gradually add the dry ingredient mixture to the butter mixture, alternating with the milk. Mix until just combined and smooth.
6. Fold in Berries: Carefully fold in the mixed fresh berries, ensuring they are evenly distributed throughout the batter.
7. Pour Batter: Pour the batter into the prepared baking pan, spreading it evenly.
8. Bake: Place the pan in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
9. Cool the Cake: Once baked, remove the cake from the oven and let it cool in the pan for 15-20 minutes. Then, transfer it to a wire rack to cool completely.
10. Dust with Powdered Sugar: Once cooled, dust the top with powdered sugar if desired for an extra touch of elegance.

These straightforward steps will guide you in creating an incredible Berry Cake that is sure to impress.