First up, gather all of your ingredients.
Time to make the pretzel curst. Get out your food processor and crush those pretzels. I used the whole bag - made just over 3 cups.
Oh, set the oven to 350 degrees and get out a glass pan.
Melt the 1 cup butter in a large bowl. Add in the pretzels and the 1/2 cup of white sugar. Mix well and then press into the bottom of the glass pan.
Top with the reese's peanut butter cups. I had to cut one row in half to make it work - just fill up the pan!
Next, time for the brownie mix. Melt the 3/4 cup of butter in a large pan. Stir in the brown sugar and the 1/2 cup of white sugar. Mix well.
After about 3 minutes, take the pan off the heat and stir in the eggs quickly - you don't want to cook them. Add in the vanilla and then add the cocoa and flour. Mix well.
Return to the heat and add in the chocolate chips until they are melted.
Pour the brownie mix over the peanut butter cups. Top with the reese's pieces and bake for 30-40 minutes.
Let it cool for about 2 hours, cut and eat!