In a mixing bowl, combine all purpose flour, granulated sugar, whole milk, melted unsalted butter, room temperature egg, vanilla extract, instant yeast, and kosher salt.

Mix until a dough forms and is smooth.

Cover the dough and let it rise in a warm place for about 1 hour or until doubled in size.

Roll out the dough on a floured surface to about ½ inch thickness.

Use a heart-shaped cutter to cut out donuts.

Place the donuts on a baking sheet lined with parchment paper and let them rise for another 30 minutes.

Preheat the oil in a deep fryer or large pot to 375°F (190°C).

Fry the donuts in batches until golden brown, about 2-3 minutes per side.

Remove from the oil and place on a cooling rack.

Once cooled, fill each donut with strawberry jam.

In a bowl, mix powdered sugar, melted butter, vanilla extract, and milk to create a glaze.

Dip the donuts in the glaze, then roll in granulated sugar or sprinkle with Valentine's sprinkles.