Preheat oven to 325 degrees. Mix together cake mix, jello, oil, 1/2 cup water and egg whites with hand mixer on medium speed for about 3 minutes. Scrap the sides of the bowl, add in the strawberry puree and food coloring. Mix until combined.
Spoon batter into greased doughnut forms 3/4 of the way up and bake for 17-19 minutes, until toothpick inserted in the center comes out clean. Let sit in tin for 5 minutes on a wired rack to cool. Take doughnuts out and cool completely on rack.
When doughnuts are cooling, make the glaze. Combine the powdered sugar, vanilla and milk or water and whisk to combine. Dip doughnuts one by one into glaze and place on wired rack. Top with optional sprinkles at this point if desired.