Preheat the oven to 350°F (175°C).
In a medium mixing bowl, whisk together your flour and baking powder, then set aside.
In a larger mixing bowl, combine the softened butter, brown sugar, and granulated sugar. Grab your hand mixer and beat them together for 1-2 minutes until everything’s light and fluffy.
Next, add the peanut butter, vanilla extract, and egg to the bowl. Mix until just combined—you don’t want to overdo it here!
Slowly fold the dry ingredients into the wet ones. Stir just until your cookie dough is fully combined.
Use a 1 1/2 inch cookie scoop (or a tablespoon) to scoop out your dough and place the balls on your lined baking sheet. Space them 2-3 inches apart so they have room to spread out while baking.
Use a fork to gently press a criss-cross pattern into the top of each cookie.
Bake for 10 minutes, just until the edges are lightly golden but still soft in the center.
While the cookies are still warm, press pretzel pieces into the tops for antlers, add a red M&M for the nose, and place two candy eyes just above it.
Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.