Mix all ingredients, except the 50 grams of chocolate chips, together in a large bowl.
Add the 50 grams of chocolate chips. You can also use chopped nuts, raisins, seeds, or coconut flakes instead.
Fill the muffin cups halfway with batter. Ensure that there is an equal amount of batter in all the cups so they bake evenly.
Place them in a preheated oven at 180 degrees Celsius (356 degrees Fahrenheit) and bake for 20 minutes. Check if they are done by feeling them with your fingertips on top. You can also prick them with a knitting needle or the tip of a paring knife.