Heat the plant milk until lukewarm and then add the active yeast, leave to bubble for a few minutes.
Sift together the flour, sugar, potato egg, vanilla seeds, and salt together.
Gradually pour in the bubbly plant milk mix and then once they are mixed gradually add bits of the vegan butter while kneading or using a bread attachment kneading slowly until homogenized.
Place in a bowl, cover with cling wrap and leave to rise for 30-60 minutes until double in size.
Once risen, wrap up in cling wrap and refrigerate overnight.
The next morning, divide the dough and save the rest to make cinnamon knots, or roll the dough out 1 ½ cm on a floured surface and press out round shapes or hearts with a cookie cutter.
Place the donuts on a floured baking tray, leave to rise until doubled and then once risen.
Heat up the canola or any other flavorless oil, add the donuts once the oil is heated to frying temperature (test with a piece of dough, its rise to the top) and fry the donuts 2-3 minutes on each side until golden brown.
Once brown on both sides, scoop out with a slotted spoon, on some paper towels to drain.
Once cooled, roll the donuts in the castor sugar, make a hole at the one end of the donut with a sharp knife or the tip of the pastry nozzle, and fill with the roasted blueberry pastry cream.
Roasted blueberry pastry cream
Preheat oven to 175°C/350°F, place the washed blueberries on a parchment paper-lined baking tray, drizzle with the maple syrup and then bake for 10-15 minutes until gooey.
Leave to cool before blending the rest of the pastry cream ingredients, pour into a saucepan on medium and stir until thickened, add more sweetness if desired.
Leave to cool before scooping into a pastry bag fitted with a wide tip nozzle to fit into the donut.
Fill with the pastry cream, and store with the pastry cream filling facing up so it does not leak out.
Serve at room temperature, best to serve fresh the day the donuts have been made.
