Preheat oven to 350°F. Spray an 8x2 baking pan with nonstick spray or line with parchment paper.
In a small bowl add flour, baking powder, salt. Set aside.
In a medium bowl whisk together the brown sugar and melted butter, add the eggs and vanilla extract.
Add the dry ingredients to the wet ingredients, stir until combined. Do not over mix.
Fold in M&M's
Spread the batter into the pan top with more M&M's. Bake for 15 minutes rotate for another 15 minutes or until a toothpick inserted into the center comes out clean. Total of 25-30minutes.