Step 1

Preheat oven to 350°F and grease a 9x13-inch baking dish with butter.

Step 2

In a large bowl, cream together the butter, granulated sugar, brown sugar, and 1/2 cup of the peanut butter with an electric mixer.

Step 3

Add egg and vanilla and mix to combine.

Step 4

Sift together flour, baking soda, and salt. Add oatmeal and stir to combine.

Step 5

Add flour/oat mixture to butter mixture and mix on low until well combined.

Step 6

Spread evenly across prepared baking pan and top with butterscotch chips.

Step 7

Bake until golden brown on the edges, 20-25 minutes.

Step 8

Whisk together powdered sugar, milk, and remaining 1/4 cup peanut butter until smooth, then pour evenly over bars while still warm.

Step 9

Let cool completely before slicing and serving. Enjoy!