Preheat the oven to 325°F (163°C).

Grease an 8-inch square metal baking pan and line it with parchment paper, leaving extra overhang for easy removal.

In a medium bowl, mix melted butter, sugar, cocoa powder, and salt until combined.

Add vanilla extract and egg, mixing until smooth.

Stir in flour until fully incorporated.

Spread the thick brownie batter evenly across the bottom of the prepared pan.

Bake for 15–20 minutes, until set.

Allow the brownie base to cool completely.

In a mixing bowl, beat butter, brown sugar, granulated sugar, and salt until light and fluffy.

Add vanilla extract and heavy cream, mixing until smooth.

Add flour and mix on low speed until incorporated.

Fold in mini chocolate chips.

Spread the cookie dough evenly over the cooled brownie layer.

Place chopped chocolate in a heat-safe bowl or measuring cup.

Heat the heavy cream in a saucepan until just boiling.

Pour the hot cream over the chocolate and let sit for 2 minutes.

Stir slowly until smooth and glossy.

Pour the ganache over the cookie dough layer and gently spread to the edges.

Refrigerate for at least 30 minutes until the ganache is firm.

Lift the dessert from the pan using the parchment paper.

Slice into 1–2 inch brownie bites.

Serve chilled.