Preheat your oven to 325 degrees, and lightly grease a 9 inch tart pan with a removable bottom. Optionally, you can use a 13x9 inch cake pan as well here lined with parchment paper for easy removal.

In a large bowl, beat together the butter and sugar until light and fluffy, about 2 minutes. Then add in the vanilla extract and stir to combine. Add in the flour and salt, and mix until well combined, and a very crumbly dough forms. Stir in the peppermint bits until well distributed.

Press the dough evenly into your prepared sheet pan. Bake for 25-28 minutes, or until the bars look dry on top and set, and the edges are just starting to brown. Cool completely in the pan, then remove and slice completely to serve.