Preheat oven to 350 degrees F. Spray donut pan with nonstick spray.
Mix together oil, buttermilk, eggs, sugar, salt, baking powder and vanilla until combined. Stir in flour and continue to mix until smooth.
Add chopped strawberries, and mix gently with a wooden spoon.
Fill the donut pans up about 3/4 of the way.
Place donuts in oven and bake for 17 minutes.
Remove from oven, let cool for 10 minutes, then remove donuts from pan.
Put sugar and cinnamon in a sandwich bag. One at a time, drop your donuts in bag and shake lightly to cover.
Eat right away or store in container. Donuts will stay fresh for 2-3 days.
If you don't have buttermilk you can substitute 1/2 cup strawberry yogurt, or make homemade buttermilk. To make buttermilk add 1 1/2 teaspoon lemon juice into a measuring cup and then fill to 1/2 mark with milk. Stir and let sit for 5 minutes. Now you have buttermilk!
Recipe Created by Pamela Reed for brooklynfarmgirl.com