Preheat oven to 350°F. Spray donut pan with non-stick spray. Set aside.
Whisk the flour, baking powder, baking soda, and salt together in a medium bowl. Set aside. Whisk together the melted butter, egg, sugar, milk, sour cream, vanilla, lemon juice, and zest until completely combined. Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix.
Spoon or pipe the batter into the donut pan, filling the cavities 2 ∕ 3 –3 ∕ 4 of the way full.
Bake for 10 minutes or until the edges become lightly browned. Allow them to cool for about 2-3 minutes and then transfer to a wire rack. Allow the pan to cool enough to handle, then bake the remaining donut batter. I usually have enough left for 2-3 more donuts. Once baked, transfer to the wire rack with the rest of the donuts. Allow them to cool completely before glazing.
For the glaze
In a small bowl, combine the strawberries, lemon juice, and granulated sugar. Allow the strawberries to macerate for about 5 minutes and then mash with a fork.
Using a fine mesh sieve, strain the strawberries into a clean medium sized bowl. Press them against the sides of the sieve with a spoon to extract all of the juices. To the strawberry "juice", gradually add the confectioner's sugar and whisk to combine. Your glaze shouldn't be too thin or too thick.
Dip the tops of the lemon donuts in the strawberry glaze and return to the wire rack to set. If desired, decorate with sprinkles before the glaze sets.
Donuts are best eaten immediately but will keep in an airtight container in the fridge for 2-3 days.