Preheat oven to 375 degrees and lightly spray a 6-cavity doughnut pan with cooking oil.
Whisk together flour, sugar, baking powder, cinnamon, and salt in a medium bowl.
In a separate bowl, whisk together yogurt, eggs, oil, and vanilla.
Pour the wet ingredients into the dry ingredients and stir until just combined. Don’t over-mix or your doughnuts will likely be too dense.
Fill each cavity about ¾ of the way full (I like to fill a ziplock bag with batter, snip a corner off, and squeeze the batter into the doughnut pan).
Bake doughnuts for 10-12 minutes until they're just turning golden and t spring back at the touch. Let doughnuts cool in pan for a couple minutes before removing to a metal rack to cool completely.
When doughnuts are completely cooled, dip in strawberry icing, add sprinkles if desired and let doughnuts sit until icing hardens.