Preheat the oven to 375 degrees.  Line a 9×13 baking dish with foil coated in cooking spray.  In a mixer bowl, cream together 1/2 cup of softened butter with granulated sugar and powdered sugar.  Add in the egg, greek yogurt, and vanilla and mix well to combine.  Add in the flour, baking powder, and salt and mix until the dough is no longer crumbly.

Press the dough into the lined baking dish.  Bake for 18-20 minutes, until just starting to turn light golden brown.  Set aside to cool completely.

For the frosting, whip the softened 1/2 cup of butter until fluffy.  Add the cream cheese and peppermint extract and mix to combine.  Add in the powdered sugar, 1 cup at a time and mix well.  

Using the edges of the foil, lift the crust out of the baking dish and slide off of the foil onto a cutting board.  Spread the frosting over the top of the cooled bars.  Sprinkle with crushed candy canes and snowflake sprinkles.  Cut into triangles to serve.