Add the strawberries and syrup to a saucepan and bring to a light boil. Break up the strawberries as it heats.
Allow it to boil and thicken then use an immersion blender/blender to get a smooth texture.
Add it back to the pot and boil to thicken again. Place in the fridge to cool.
Preheat oven to 375F
Mix the oat flour, baking powder, and stevia together until no clumps remain.
Add in the eggs, vanilla, and yogurt. Mix thoroughly.
Add the batter to a plastic bag to pipe into the doughnut tin.
Divide half the the mixture between 5 wells.
Evenly divide the strawberries between each well.
Top with the remaining doughnut batter.
Bake for 9-10 minutes.
Allow the doughnuts to cool completely.
Mix the powdered peanut butter, honey, and water. Top each doughnut with the frosting.