Prepare the Brownie Base

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper for easy removal.
2. Mix the Wet Ingredients: In a large mixing bowl, whisk together the melted butter, granulated sugar, and brown sugar until smooth. Add the eggs one at a time, whisking well after each addition. Stir in the vanilla extract.
3. Add the Dry Ingredients: In a separate bowl, sift together the flour, cocoa powder, salt, and baking powder. Gradually fold the dry ingredients into the wet mixture, mixing until fully combined.
4. Pour into Pan: Pour the brownie batter into the prepared pan, spreading it evenly with a spatula.
5. Bake: Bake the brownies in the preheated oven for 45-50 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Keep an eye on them towards the end to avoid overbaking.
6. Cool: Allow the brownies to cool in the pan for 10-15 minutes before transferring them to a wire rack to cool completely.

Prepare the Butterscotch Layer

1. Melt the Butterscotch: While the brownies are cooling, combine the butterscotch chips and heavy cream in a microwave-safe bowl. Heat in 30-second intervals, stirring in between, until the mixture is smooth and fully melted.
2. Drizzle Over Brownies: Once the brownies have cooled, drizzle the melted butterscotch over the top, spreading it evenly with a spatula or spoon.
3. Add Sea Salt: Sprinkle the sea salt evenly over the butterscotch layer for that irresistible contrast.