01 -
Set your oven to 350°F (175°C) and cover a square baking pan with parchment paper.
02 -
In a bowl that’s safe for the microwave, heat the butter until melted. Stir in the sugar, eggs, and vanilla, mixing well. Sprinkle the cocoa, flour, and salt on top, then combine everything until smooth and lump-free.
03 -
Grab a separate large bowl and cream the softened butter with the sugars. Beat in the egg and vanilla until fluffy and light. Slowly fold in the flour, baking soda, and salt until you get a soft dough. Gently stir in the chocolate chunks until they’re mixed in evenly.
04 -
Spread the brownie mix evenly into the prepared baking pan. Scoop chunks of the cookie dough on top of the brownie layer, then press lightly to create swirls or a marbled look.
05 -
Pop it into the oven and bake for about 30-35 minutes. The edges should set while the middle stays a little soft.
06 -
Take it out and let it cool completely in the pan. Once it’s cooled down, cut it into squares or whatever shape you like, then enjoy.