Blend the flaxseeds and soak with water for about 5 min
Whisk sugar and flaxseeds creamy in a bowl
Add the milk
Melt the butter on the stove in a saucepan and whisk it in the dough
Mix flour and baking powder and add it to the dough
Rinse the rhubarb and cut them in smaller pieces
Stir rhubarb into the dough
Put cupcake liners in a muffin pan
Pour dough into each cupcake liners till they are full
Bake the muffins in the oven at 200° C for 20-25 min