Crush the pretzels in a food processor or however you like to crush pretzels. Any kind of pretzels will do but I recommend using crushed butter pretzels for the recipe (you find them next to the regular pretzels and they are literally called “Synder Butter Pretzels”). I also recommend not crushing the pretzels to dust but keep some small pieces to keep the crust crunchy. Mix the melted butter (melt in microwave), sugar and pretzel crumbs. Press into lightly greased 13×9 pan. Set aside pretzel crust and make the cookie dough. (*Note: I have a 8×8 pan in the photos because I split the recipe into two different pans. I recommend putting it all in one 13×9 pan!)
Make the sugar cookie dough according to the package. If you want to make the sugar cookies from scratch, here's how: Cream together 1 1/2 cups butter and 2 cups sugar until smooth. Beat in 4 eggs and 1 tsp vanilla. Stir in the 5 cups of flour, 2 tsp baking powder and 1 tsp salt. There you have it - sugar cookie dough! Add 1 cup Heath Bits and mix thoroughly.
Lightly press the cookie dough evenly on top of the pretzel crust. The easiest way I found to add the sugar cookie layer is to literally roll the dough out like you would with cut out cookies.
Set the pan on top and cut out a large rectangle so the dough fits into the pan. Lightly press the dough to the edges.
Whip up your brownie mix and pour evenly over the sugar cookie layer.
Evenly distribute brownie batter to the sides.
Bake at 350 degrees for 40-45 minutes.
Cool for 10 minutes and then enjoy!