In a large mixing bowl, cream the butter and sugars at medium speed with an electric mixer until light and fluffy.
Add the eggs and vanilla; continue beating until well combined.
In a separate bowl, sift together the flour, baking powder, baking soda, and salt.
With the mixer on low speed, gradually add the dry ingredients to the creamed mixture, about one-third at a time, mixing just until combined after each addition.
Gently fold in the pretzels, coconut, and M&M’s.
Refrigerate the dough for 30 minutes. While the dough chills, preheat the oven to 350°F.
Scoop about 2 tablespoons of dough and roll into balls. Place on a greased or lined baking sheet about 3 inches apart.
Bake the cookies for 12–14 minutes, or until the cookies reach your desired level of doneness.
Remove the cookies from the pan and cool on wire racks.
Notes
Chilling the dough helps prevent spreading and improves flavor.
For softer cookies, remove from the oven when centers are slightly underbaked.
You can substitute chocolate chips for M&M’s if preferred.