Preheat oven to 400°. Grease a donut pan well and set aside.

Combine flour, baking powder, baking soda, and salt in a small bowl. Set aside.

In a large bowl, whisk together the egg and sugar. Add the milk, oil, and vanilla and mix until well combined. Add the dry ingredients and stir just until combined.

Fold in the chopped strawberries.

Spoon the batter into the prepared donut pan. Each donut well should be about ¾ full.

Bake for 10-12 minutes or until a toothpick inserted in the middle comes out clean.

Cool for 10-15 minutes before transferring the donuts to a wire rack.

Combine the jam, vanilla, and powdered sugar in a small bowl. Slowly add the milk, whisking the glaze until it reaches the desired consistency. Dip the top of each donut in the glaze and return the donuts to the wire rack. Let the glaze set up for about 30 minutes before serving.