Prepare the Brownies:

• Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving some overhang for easy removal.
• In a large mixing bowl, whisk together the melted butter and sugar until smooth.
• Add in the eggs and vanilla extract, and whisk until fully combined.
• Sift in the cocoa powder, flour, salt, and baking powder. Fold the dry ingredients into the wet mixture until just combined. Do not overmix.
• Pour the batter into the prepared pan, spreading it out evenly.
• Bake for 18-20 minutes, or until a toothpick inserted into the center comes out mostly clean. Remove from the oven and let cool completely.

Cut the Brownies:

• Once the brownies are fully cooled, use the parchment paper to lift them out of the pan.
• Cut the brownies into an even number of squares or rectangles, depending on the size you prefer for your sandwiches.

Assemble the Sandwiches:

• Allow the ice cream to soften slightly at room temperature for about 5 minutes to make it easier to spread.
• Take one brownie square and spread a generous layer of ice cream on the flat side. Top with another brownie to make a sandwich.
• Repeat with the remaining brownies and ice cream.
• Place the assembled sandwiches on a baking sheet and freeze for at least 2 hours or until the ice cream is firm.

Serve:

• Let the sandwiches sit at room temperature for a few minutes before serving to make them easier to bite into. Enjoy!