Preheat the oven to 325º F. Spray a donut pan with cooking spray, use a paper towel to lightly spread/remove excess spray.
In a large bowl, combine the flour, sugar, baking powder and salt.
In another bowl, combine the milk, eggs, vanilla, and oil. Stir the dry ingredients into the wet ingredients adding the chopped reese's as well, mix just until combined.
Transfer the batter to a large piping bag or use a ziploc bag with one corner cut off. Pipe the batter into the donut pan, filling each donut hole about 2/3 full.
Bake the donuts for 10 minutes, or until a toothpick comes out clean. Remove from the oven and let the donuts sit in the pan for 5 minutes before removing them from the pan. Cool completely before dipping.
Combine the chocolate and oil in a shallow microwave safe bowl and microwave on 60% power, stirring every 30 seconds for about 2 minutes. You do not want the chocolate to be too runny. Let the chocolate sit for a few minutes so it can thicken before you dip the donuts into the chocolate. Dip each donut into the chocolate, allowing the excess to fall off. Let the chocolate covered donuts sit for 3-4 minutes before adding the peanut butter drizzle.
Peanut Butter Drizzle
Combine the peanut butter and oil in a shallow microwave safe bowl, and microwave on 60% power for 1-2 minutes, or until the peanut butter is melted. Drizzle the peanut butter over each donut, using a spoon.
Serve and enjoy or store in a tupperware container.