1 box (18.3 oz) brownie mix (plus eggs, oil, and water called for on the box)
1/2 cup creamy peanut butter
1/2 cup quick-cooking oats
1/2 cup candy-coated chocolate pieces (M&Ms)
1/4 cup semi-sweet chocolate chips
1/4 cup white chocolate chips
1 tablespoon candy eyes (optional, for a monster look)
Instructions
Preheat your oven to 350°F (175°C). Lightly grease a 12-inch round pizza pan or a large tart pan with non-stick cooking spray or a little bit of butter to ensure the brownie doesn’t stick.
In a large mixing bowl, prepare the brownie mix according to the package instructions using the required eggs, oil, and water. Once combined, stir in the creamy peanut butter and the quick-cooking oats until the batter is smooth and well-incorporated.
Pour the batter onto the prepared pizza pan. Use a spatula to spread it evenly toward the edges, leaving a small gap near the rim as it will expand slightly while baking.
Sprinkle the candy-coated chocolate pieces, semi-sweet chocolate chips, and white chocolate chips evenly over the top of the brownie batter. Press them down very lightly so they stick but don’t sink completely.
Place the pan in the oven and bake for 20 to 25 minutes. You want the edges to be set, but the center should still be slightly soft. Avoid overbaking to keep that fudgy brownie texture.
Remove the pan from the oven and let it cool completely on a wire rack. If you are using candy eyes, press them into the top while the brownie is still slightly warm but not hot enough to melt them. Once fully cooled, slice into 12 wedges.