First you'll need to get your bacon cooked and to reserve your bacon grease. This is how I do it.
Preheat oven to 375 degrees. Place a cooling rack inside a jelly roll pan.
Line your strips of bacon side-by-side. If you run out of room, add the extras on the layers of bacon already down. Check on it periodically. As the bacon shrinks, there will be more room for the extra pieces.
After about 25 minutes, flip the bacon over. Let bake fro another 10 minutes. Check to make sure it's done to your preference before you remove it from the oven. I like mine more chewy than crispy.
Place on a plate lined with paper towels to cool.
Pour the bacon drippings into a heat proof bowl to cool.
Preheat oven to 350 degrees. Spray a donut pan with non-stick cooking spray.
In a mixing bowl, add in the bacon grease/drippings and peanut butter. Mix on medium until incorporated.
Add in the granulated and brown sugar. Mix on high until light and fluffy about 2 minutes.
Add in the maple extract, vanilla beat paste or extract if you don't have paste on hand, sour cream, eggs and milk. Mix on low until incorporated.
Add in the baking powder, baking soda, salt and flour and mix on low until the flour is almost incorporated and it's safe to turn it on high.
Turn on high for a few seconds to incorporate the rest of the flour.
Stir in the bacon with a spatula.
Place the batter in a large freezer bag. Press out all the air and seal the bag. Cut the corner out of the bottom of one side.
Pipe in one layer of batter into the prepared donut pan. Add any batter to spots that don't have an even amount.
Place in the oven and bake for 13 minutes or until done. The sides will be golden brown. Remove from the pan.
Spray the pan before adding batter each time to prevent sticking. Repeat with the rest of the batter.
Let the donuts cool completely.
In a microwave-safe bowl, melt the peanut butter for about 50 seconds.
Add in the maple extract, milk and powdered sugar. Whisk until the glaze is completely smooth.
Dip the bottoms of the donuts which will now be the tops in the glaze. Sprinkle on the crumbled pieces of bacon and set aside to dry. Repeat with all donuts.