Combine the dry ingredients in a medium bowl and stir.
Add the milk, egg and melted butter to dry ingredients and stir to combine thoroughly.
Add the rhubarb jam to the donut batter - stir to incorporate.
Spray your donut pan with non-stick spray and pre-heat oven to 400°
You can spoon the batter into the donut pan or I like to put the batter into a ziplock bag or a pastry bag - cut a small hole and pipe the batter into the pan.
This recipe makes exactly 12 donuts in the size pan that I use.
Bake for 8-10 minutes until donuts are firm to the touch on top. Allow to cool for a few minutes in the pan than remove from the pan and allow to cool on a cooling rack.
I dusted with powdered sugar.