Add blueberries and lemon juice to a small pan and bring to a boil over medium heat. Lower heat and continue to simmer for 10-15 minutes or until the blueberries have burst and the sauce thickens slightly.
Remove blueberries from heat and allow to cool slightly. Add to a food processor and blend until mostly smooth. Set aside.
Pre-heat oven to 350 degrees.
Sift dry donut ingredients into a bowl (except poppyseeds). Whisk an egg until frothy and add poppyseeds and remaining wet ingredients to the dry ingredients. Fold together just until combined.
For best results, spoon donut batter into a piping bag and pipe batter into donut pan.
Bake at 350 degrees for 15-18 minutes or until a toothpick inserted into the thickest part of the donut comes out clean.
Once donuts have cooled, whisk blueberry sauce with confectioner's sugar/powdered sugar. Dip donuts into glaze and allow to set up slightly before serving.
Due to the use of sugar alcohols (11 grams) in the Monkfruit sweetener and confectioner's sugar, the MFP barcode for this recipe only shows 7 grams of carbs per donut. Read more about how sugar alcohols impact macro/calorie counts here.