Preheat the oven to 350°F (180°C). Line two 12 cups and one 6 cups muffin/cupcake pans with cupcake liners.
Sift all-purpose flour, baking powder, and salt into a medium sized bowl.
Cream butter, cream cheese, and sugar in a large bowl until light and fluffy, about 2 minutes.
Beat in eggs, one at a time until combined.
Add vanilla extract and beat for 30 seconds.
Add half the milk and half of the flour mixture. Beat on low speed. Then add remaining milk and flour mixture. Continue to beat until combine.
Fold in 1 cup (200g) M&M semi sweet dark chocolate baking bits.
Fill cupcake liners until about 2/3 full.
Place remaining M&Ms on the tops of each cupcake batter.
Bake for 20 minutes or until a tester inserted in the center of the cakes comes out clean.
Cool cupcakes in pan for 10 minutes, then remove and cool on a rack.