• Preheat the oven to 375 degrees Fahrenheit. Line a rimmed half cookie sheet (13x18x1) with parchment paper, or spray with nonstick spray. 
• In a large bowl, combine the old fashioned oats, flour, baking powder, and salt. Set aside. 2 1/3 cups old fashioned oats, 1 1/2 cups flour, 1 tsp baking powder, 1/2 tsp salt
• In a large mixing bowl, mix together your peanut butter and butter. 1 cup creamy peanut butter, 1 cup Unsalted butter
• Add in the sugar and brown sugar and cream together till smooth, and light.  2/3 cup Granulated sugar, 1 1/3 cup Brown sugar
• Add in the eggs, and vanilla and stir to combine. 2 eggs, 1 tsp vanilla
• Add the dry ingredients to the wet ingredients and stir it all together. 
• Press the cookie dough into the cookie sheet, spreading evenly to the edges. The dough is pretty sticky, so spray your hands or a rubber spatula with nonstick spray while you spread it. 
• Bake in the preheated oven for 15 minutes, until the middle is just barely set. 

For Topping the Bars:

• Allow the bars to cool for about 5 minutes, then drop peanut butter dollops over the top of the bars.  1 cup peanut butter
• Allow to sit for about 1-2 minutes until the peanut butter starts to soften, then spread the peanut butter evenly over the top. 

For the Chocolate Icing:

• In a medium sized heavy sauce pan over medium heat, add butter, milk and cocoa powder, and cook until the butter melts and the mixture just comes to a boil. Then remove from the heat. 1/2 cup Unsalted butter, 6 TBS Whole Milk, 4 TBS cocoa powder
• Whisk in the powdered sugar till smooth. 3 1/2 cups powdered sugar
• Pour the icing over the top of the bars and spread into an even layer. 
• Allow frosting to set and bars to cool completely before cutting into squares to enjoy. 
• Store bars in an airtight container at room temperature for 5-6 days.