Peppermint Sugar Cookie Bars

1 cup (2 sticks) butter, softened
2 cups granulated sugar
4 eggs
2 tsp vanilla extract
5 cups flour
1 tsp salt
1/2 tsp baking soda
1 can vanilla frosting
1/4 tsp peppermint extract
15 crushed peppermint candies

Preheat oven to 375. Line a 13x9 pan with parchment paper, and coat lightly with cooking spray.
In a medium bowl, combine the flour, salt, and baking soda. Set aside.
In the bowl of a stand mixer, cream together the butter and sugar, until light and fluffy.
Add in the eggs one at a time, beating well after each addition, then beat in the vanilla.
Gradually add in the flour mixture, and beat until combined.
Spread the batter evenly in the pan, smoothing out the top.
Bake for about 25 minutes, or until a toothpick inserted in the center comes out clean.
Remove from the pan, and place on a wire rack to cool.
While the bars are cooling, stir the peppermint extract into the can of frosting, and mix thoroughly.
Once the bars have cooled completely, even spread the frosting across the top.
Crush the peppermints in a plastic bag with a rolling pin, and spread evenly over the top of the bars.
Cut into bars and serve.