First Step: Get ReadyPreheat your oven to 350°F (180°C). Grease and line a 9-inch springform pan or an 8-inch cake tin with parchment paper to prevent sticking, allowing neat removal of the brownie crust after baking.

Second Step: Make the Brownie BatterIn a large bowl, whisk the softened unsalted butter with granulated sugar until creamy and fully combined. Add the eggs one at a time, beating well after each addition. Stir in the pure vanilla extract to infuse flavor.

Third Step: Mix Dry IngredientsSift together cocoa powder, all-purpose flour, salt, and baking powder. Gradually incorporate the dry ingredients into the wet mixture, folding gently until a thick, smooth batter forms. This careful mixing prevents overworking the batter and keeps the brownie dense yet tender.

Fourth Step: Bake the Brownie CrustSpread the brownie batter evenly across the bottom of the prepared pan. Bake for 30 to 40 minutes or until the top cracks slightly and a toothpick inserted near the center comes out mostly clean (a few moist crumbs are fine). Avoid overbaking to keep the crust fudgy. Remove from the oven and allow it to cool completely while still in the pan.

Fifth Step: Prepare and Layer the Ice CreamSlightly soften half a gallon of vanilla ice cream by leaving it at room temperature for 5 to 7 minutes just enough to become spreadable but not melted. Spread the softened vanilla ice cream evenly over the cooled brownie crust. Place the pan in the freezer and freeze for at least 3 to 4 hours or until the layer is firm and solid.

Sixth Step: Add Strawberry Ice Cream LayerNext, soften half a gallon of strawberry ice cream similarly. Spread it evenly over the frozen vanilla ice cream layer, smoothing the top. Return the cake to the freezer for another 3 to 4 hours or ideally overnight, allowing all layers to fully set.

Seventh Step: Optional Garnish and FinishIf desired, bake a second batch of brownies and let cool completely. Cut them into small chunks for adding as a textured topping. When the layered cake is fully chilled, run a hot knife around the edges to loosen it from the pan. Remove the springform collar carefully, then top the cake with brownie pieces and drizzle melted chocolate for extra indulgence.

Final Step: Serve and EnjoyBefore serving, let the cake sit at room temperature for 7 to 10 minutes to slightly soften the ice cream for easier slicing. Use a knife dipped in hot water to make clean cuts without cracking the brownie crust.