Preheat the oven to 350°F, place a rack in the middle of the oven, and lightly grease a doughnut pan (I used non-flavored cooking spray). Place sliced strawberries in a small food processor, and pulse until very finely chopped (or a chunky puree). You can also do this by hand. Measure out 1/4 cup of finely chopped strawberries for the doughnut batter, and another 1/4 cup for the glaze. Save leftovers for morning pancakes or evening ice cream.

Sift flour, baking powder and baking soda into a large bowl. Whisk in sugar and sea salt, then set aside. In a medium bowl, whisk together butter, buttermilk, vanilla, lemon juice, egg, and 1/4 cup finely chopped strawberry until well combined. Add the liquid mixture to the bowl with the dry ingredients, stirring just until combined. Do not overmix here. If the mixture looks a little on the thick side, stir in a splash of buttermilk to loosen it up a bit.

Fill the wells of the doughnut pan 3/4 of the way with batter. I used a pastry bag here, but you could also do this with a spoon. Bake until the doughnuts spring back when touched (9 - 10 minutes), and the bottom of the doughnuts are lightly golden (the side that's cooking in the well). Let the doughnuts cool for 2 minutes in the pan, then transfer to a rack to cool completely.

While the doughnuts are cooling, prepare the glaze. In a small bowl, whisk together confectioners' sugar and buttermilk until smooth. Stir in 1/4 cup finely chopped strawberry. Dip one side of each doughnut into the glaze, then place back on the cooling rack. I set my cooling rack over a piece of parchment paper to catch dripping glaze. Let the glaze set, then enjoy!