Preheat your oven to 350 degrees Fahrenheit and spray cupcake tins with cooking spray.
In a small bowl, whisk together the whole wheat pastry flour, erythritol, starch, protein powder, baking powder and salt.
**For the strawberries- rinse the berries, slice the greens off, and puree in a blender until completely smooth.
In a stand mixer bowl with beater attachment, add the strawberry puree, yogurt, eggs, stevia extract, vanilla extract, and strawberry flavor. Mix on low speed until completely mixed.
Turn off the stand mixer and dump in the dry ingredients. Mix on low speed, then increase the speed to medium. Mix until JUST incorporated, you don't want to overmix this! Add the vinegar and quickly fold in with a spoon or spatula.
Scoop the batter into the prepared cupcake tins and bake for ~25 minutes, or until the cupcakes spring back when tapped. Let cool in the pan for 5 minutes, then transfer to a wire cooling rack to cool completely.