Preheat the Oven:

• Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper.

Prepare the Brownie Batter:

• In a medium saucepan, melt the butter over medium heat. Remove from heat and stir in the granulated sugar until well combined.
• In a large mixing bowl, whisk together the eggs and vanilla extract. Gradually add the butter and sugar mixture, whisking constantly until smooth.
• Stir in Dr Pepper soda. In a separate bowl, sift together the flour, cocoa powder, baking powder, and salt.
• Add the dry ingredients to the wet mixture, stirring until just combined. Pour the batter into the prepared baking pan.

Bake the Brownies:

• Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
• Allow the brownies to cool completely in the pan before glazing.

Prepare the Dr Pepper Glaze:

• In a small saucepan, combine Dr Pepper soda, butter, and cocoa powder. Cook over medium heat, stirring until smooth.
• Remove from heat and whisk in powdered sugar and vanilla extract until the glaze is smooth and glossy.

 Glaze the Brownies:

• Pour the glaze over the cooled brownies, spreading it evenly with a spatula. Allow the glaze to set before cutting the brownies into squares.