Grind nuts, grate Zucchini and Lemon Zest -> Squeeze zucchini shreds, so you don't have too much liquid in the dough.
Mix spelt flour, walnuts, baking powder, brown sugar, vanilla extract, and salt together and oat milk as well as coconut oil separately including zucchini and lemon shreds.
Then stir wet ingredients into dry ingredients.
Divide batter into muffin tin and bake the muffins for about 15 - 20 minutes (or do the toothpick test - as soon as it comes out clean the muffins are ready).