Cover a cookie sheet with parchment paper. Place 50 pretzels all over the parchment paper and top each one with an unwrapped rolo candy. Set aside.
In a medium bowl mix together peanut butter, powdered sugar, melted butter and milk until smooth and creamy. Spread a little of the peanut butter mixture on the other 50 pretzels.
Heat oven to 300 degrees and place the cookie sheet with the pretzels and rolos in the oven for about 3 minutes.
Remove from oven and top with the peanut butter pretzels and press gently to make a sandwich. (Peanut butter side down!)
Place the cookie sheet in the freezer for about 20 minutes to set up.
Melt 2 cups of the chocolate chips with 1/4 teaspoon of oil in the microwave. Stir until smooth. Dip each pretzel sandwich in the chocolate and shake off excess chocolate. (I used a plastic fork with the center prongs broken off. Place back on the parchment lined cookie sheet. You can stick it in the fridge to set up.
Then melt 1/2 cup of chocolate chips and put in a sandwich baggie and snip the corner. Pipe the chocolate onto each of the pretzel squares.