Put all the dry ingredients in a large mixing bowl or bowl of your stand mixer. Make sure to keep yeast away from salt and sugar at this point. Give it all a good mix with a whisk or paddle attachment (if using stand mixer).

Put butter in a small saucepan/milk pan and melt it gently over low heat. Once melted, take it off the heat, add oat/soya milk and vanilla extract (if using) and give it a little stir.

Next, add lemon zest directly into dry ingredients (if using) and pour in butter mixture.

If using stand mixer, knead the dough (using dough hook attachment) for good 5-10 minutes until it becomes soft and elastic. If kneading by hand you will have to allow longer kneading time.

Put the dough back into lightly oiled bowl, cover it with a clean tea towel and put it somewhere warm to proof and double in size. It will take anything from 1-2 hours depending on the temperature of the environment it's in.

Prepare the filling by washing and drying blueberries and mixing them gently with icing sugar and cornflour.

Punch your risen dough to deflate it, give it a quick knead and divide into 16 equal pieces.

Flatten each piece of dough roughly to the size of your palm and fill it with a generous tablespoon. Seal the bun really well as if you were sealing a dumpling and shape them gently in your hands to form a roll.

Place seam side down on prepared baking tray allowing some space for expansion. Repeat with all the other buns.

Once filled, let the rolls proof again on baking trays for approx 20-30 min (covered with clean tea towel).

As you wait, preheat the oven to 180C/350F/Gas Mark 4.

Once puffed up and ready for the oven you may choose to brush the buns with some vegan 'egg wash'. Mix some plant milk and maple syrup together in a little bowl and gently brush over the buns.

Bake in preheated oven for approx 20 min or until nicely browned.

Once baked, take them out onto the cooling rack and let them cool completely before icing.

Prepare the lemon glaze by mixing icing sugar with lemon juice to reach desired consistency and brush or spoon gently over cooled buns.