Preheat oven to 350°F. In a medium bowl, whisk together the flour, baking powder & salt. Set aside.
In a large bowl, beat butter and sugar with an electric mixer for 3 minutes. Add the egg and vanilla and beat another minute. With the mixer on low, gradually add the flour mixture. Blend until the dough begins to pull away from the sides of the bowl. Place on a large piece of parchment paper. Use your hands to knead the dough for a few minutes. Roll out the dough on lightly floured surface.
With a triangular cookie cutter, cut out 12 cookies and bake according to directions. Allow the cookies to cool on a wire rack before decorating.
Using a stand mixer or an electric mixer, beat softened butter, sugar and milk. Add gel food coloring until completely tinted. The buttercream is ready once it is smooth and forms semi-stiff peaks. Using a frosting bag, frost each cookie in a back and forth motion.
Break your mini pretzel sticks into thirds and place one on the bottom of each cookie. Sprinkle with candies and happy holidays!
Notes
How do I store the decorated cookies? Store them in a single layer in an airtight container at room temperature for up to 3 days. If stacking, use parchment paper between layers to prevent smudging.