Begin by preheating your oven to 350°F (175°C) to ensure even baking.
Line a baking sheet with parchment paper to prevent sticking.
In a large mixing bowl, combine the melted or softened unsalted butter with the yellow cake mix. Stir until well blended. Add in the eggs and mix until smooth and creamy.
Gently fold in the M&Ms until evenly distributed. Reserve some for pressing on top before baking.
Drop rounded balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, until the edges are lightly golden.
Remove from the oven and let cool on the baking sheet for about 5 minutes before transferring to a wire rack.
