In a medium bowl, whisk together flour, baking powder, and salt. Set aside
In a large bowl using an electric mixer, beat together butter, sugars, and vanilla extract on medium speed; mix until smooth. Beat in eggs on low speed, 1 at a time; just until combined.
Add flour mixture; mix just until combined. Gently fold in M&M's Chocolate Candies.
Spread batter evenly into prepared pan.
Bake for 25-35 minutes or until evenly browned and edges are puffed. Cool completely on wire rack. Cut into bars. Eat & Enjoy!
Notes
M&M Cookie Bars should be stored in an airtight container; will keep 3 days.