01 -
Turn your oven on to 350°F (175°C). Either grease an 8-inch cast-iron skillet or line it with parchment paper to avoid sticking.
02 -
In a smaller bowl, mix the flour, baking powder, and salt really well, then put it aside for later.
03 -
In a larger mixing bowl, mix the melted butter, brown sugar, and granulated sugar using a mixer or even just a spoon. Once it’s smooth, throw in the egg and vanilla and give it another mix until combined.
04 -
Pour the dry ingredients into the wet mixture and stir until everything's just mixed together. Don’t overdo it—stop once you don’t see any dry flour bits.
05 -
Gently fold in 3/4 cup of the M&Ms so they’re spread evenly throughout the cookie dough.
06 -
Take your dough and press it flat into the pan, making sure it’s nice and even across the bottom.
07 -
Pop it in the oven for anywhere from 15 to 20 minutes. It’s done when the edges get a golden color, and the middle is set but still slightly soft.
08 -
Take the skillet out and place it on a wired rack. Let the cookie cool down for 10 minutes while still in the skillet.
09 -
In a microwavable bowl, melt your milk chocolate chips. Start by warming them for 30 seconds, then stir. If they’re not fully melted, keep heating in 15-second bursts, stirring after each one until smooth.
10 -
Pour the melted chocolate over the warm cookie and spread it out evenly. Quickly press on the rest of the M&Ms while the chocolate’s still wet so they stick.
11 -
Leave the cookie for 15 to 20 more minutes, giving the chocolate topping time to harden and the cookie to cool completely.
12 -
Cut the cookie into pizza-style wedges and serve. Use a sharp knife, and for cleaner slices, wipe the blade after each cut.