Preheat the oven to 350 degrees and line 2 baking sheets with parchment paper.
In a medium mixing bowl, beat the butter, brown sugar, and granulated sugar until fluffy, about 2-3 minutes.
Add in the eggs one by one, mixing after each. Add in the vanilla and mix again.
Fold in crushed M&M’s and toffee pieces.
Using a 1 3/4″ cookie scoop (or something close to that measurement), add scoops of dough to the cookie sheets. Bake for 10-12 minutes or until the edges are lightly golden. Cool on the sheets for 5 minutes and then move them to wire racks to cool completely.
Repeat the baking process with the rest of the dough.