Combine the oat flour, whey protein, coconut and marmalade in a bowl.
Add a tiny bit of milk and mix everything through with your hands, add a little bit more milk and continue to mix everything until the consistency resembles a bread dough. You don't want to add to much liquid or you won't be able to shape the bars.
Once you have the desired thickness, shape the mixture into several bars and place them on a plate that has been covered with grease-proof paper. Pop them into the freezer for 30 minutes to firm up.
This recipe makes 4 bars at 300kCal and 3 bars at 400kCal