Spray pan with cooking spray, use a good amount. You don’t want the donuts to stick to the pan.
In a large bowl, combine cake mix, egg, oil, and water. Mix well until all of the ingredients are combined.
Pour mixture into a large ziplock bag, cutting one corner of the bag. Pipe batter into donut pan. Only fill half way. The donuts will rise, if they’re too full they’ll fall apart when you take them out.
Bake in oven for 10-12 minutes or until a toothpick comes out clean.
Remove donuts from oven, and allow them to cool for a few minutes before moving them to a cooling rack.
For the icing, mix the confectioners sugar and milk together until it forms a creamy icing and all lumps are gone.
Place cooled donuts on parchment paper and pour icing over the top of them. Top with sprinkles or chopped strawberries. Allow icing to harden a bit before diving in.