Preheat your oven to 350°F (175°C).
In a large bowl, cream together the softened butter and powdered sugar until light and fluffy.
Add the egg and vanilla extract, mixing well.
In another bowl, combine the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, mixing until combined.
Divide the dough in half; color one half with red food coloring and leave the other plain.
Roll out one tablespoon of each color into long strands.
Twist the red and white strands together, then form into a candy cane shape.
Place the cookies on a lined baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes or until the edges are lightly golden.
Remove from the oven and sprinkle with crushed candy canes while still warm.