170g unsalted butter
150g granulated sugar
1 large egg + 1 egg yolk
2 tsp vanilla paste or extract
218g all-purpose flour
½ tsp baking powder
½ tsp baking soda
½ tsp salt
120g regular M&Ms
80g mini M&Ms
Let the butter melt in a small metal saucepan. Once melted, let it cook for around 3-4 minutes until the milk solids have caramelized and the butter smells nutty.
Bake the cookies for 9-10 minutes until they have puffed and the edges are golden brown. They will continue cooking on the hot oven tray once out of the oven and firm up as they cool down.