1. Prepare the Butterscotch Sponge Layers

1. Preheat oven to 350°F (175°C). Grease and flour two 9-inch cake pans or line with parchment paper.
2. In a medium bowl, whisk together flour, baking powder, and salt.
3. In a large bowl, beat butter and brown sugar until light and fluffy.
4. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
5. Alternate adding the dry ingredients and buttermilk, beginning and ending with dry ingredients.
6. Stir in cream soda for a hint of Butterbeer magic.
7. Divide batter evenly between the prepared cake pans and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
8. Let cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

2. Make the Blackberry Filling

9. In a small saucepan over medium heat, combine blackberries and sugar.
10. Cook, stirring occasionally, until blackberries begin to break down and release their juices.
11. Mix cornstarch with water to create a slurry, then stir it into the blackberry mixture.
12. Simmer until thickened, about 2-3 minutes, then remove from heat and let cool completely.

3. Create the Butterbeer Frosting

13. In a large bowl, beat butter until smooth and creamy.
14. Gradually add powdered sugar, mixing well.
15. Pour in cream soda and vanilla extract, then beat until light and fluffy.

4. Assemble the Cake

16. Place one cake layer on a serving plate. Spread a generous amount of blackberry filling on top.
17. Add the second cake layer and frost the entire cake with butterbeer frosting.
18. Use a spatula to smooth the frosting, then add decorations as desired.

5. Decorate & Serve

19. Dust with edible silver or gold shimmer to create a magical, Forbidden Forest glow.
20. Garnish with fresh blackberries and chocolate leaves or vines for a forest-inspired look.
21. Slice and serve your Butterbeer Layer Cake at Hogwarts feasts, Halloween parties, or magical baking nights!