Preheat oven to 325 degrees and spray a donut pan with nonstick spray.
Mix peanut butter and sugar until fluffy. Add milk, oil, egg and vanilla and continue to mix.
In separate bowl combine flour, baking powder, cinnamon and salt. Then pour this dry mixture into your wet mixture. Mix until combined.
Pour into your donut pan bake 9-10 minutes.
Let cool for a few minutes.