Move oven rack to middle position and preheat oven to 350 degrees F. Spray 9x13-inch baking pan with nonstick cooking spray and set aside.
In a small bowl whisk together flour, baking powder, and salt; set aside.
In a bowl of a stand mixer add butter and sugar and mix on medium speed until light and fluffy, about 2 minutes.
Add egg and vanilla and mix until combined.
Add flour mixture and mix to combine (the dough should look crumbly).
Pat dough into the bottom of prepared 9x13-inch baking pan and bake for 22-25 minutes or until edges are golden brown. Move pan to wire rack and cool for 1 hour.
Place chocolate chips and vegetable shortening in a microwave-safe bowl, and cook on 50% power for 1 minute. Stir and microwave for 30 seconds and stir. Repeat until chocolate is completely melted.
Spread melted chocolate over cookie crust and spread into an even layer. Sprinkle crushed candy canes over the top. Place pan in the refrigerator for 1 hour, or until chocolate is set. Cut into triangles and serve.