1. Add all main ingredients (oat flour, tahini, vanilla protein, maple syrup, lemon juice, 1 tbsp lemon zest, pinch of salt) to a bowl and mix well using your hands or a spatula.
2. If the mixture is too wet, add more oat flour, 1 tablespoon at a time, until desired consistency is reached.
3. If the mixture is too dry, add a little more tahini, 1 tablespoon at a time, until desired consistency is reached.
4. Roll the mixture into 16 balls.
5. Place the rolled balls in the fridge to firm up while you prepare the topping.
6. Melt the white chocolate in a separate bowl.
7. Whisk in some additional lemon zest into the melted white chocolate.
8. Once the protein balls are firm, add about 1 teaspoon of the melted white chocolate and lemon zest topping onto the top of each ball, allowing it to drip down the sides.
9. Store the finished protein balls in the fridge or freezer for best keeping.