Put in the Thermomix flour, baking powder, cinnamon and the lemon peel. Mix on progressive speed 5-10. Put on a separate bowl
Put the butterfly on and add eggs and sugar. Mix during 3 min at 37º, speed 3.5. Once done, program again 3 min, speed 3.5
Add the milk, oil and salt and mix 10 seconds on speed 2. Take out the butterfly.
Add the flour with the rest of the ingredients in the bowl from step 1 and mix 15 seconds on speed 3. Finalise mixing with a spatula by hand and let the dough rest in the fridge for at least 1 hour or until the next day.
Pre-heat the over at 250
Mix slightly the dough from the fridge and pour on muffin paper cases placed inside a muffin form. Place it in the oven, lower the temperature to 210 and bake for 14-16 min.
Notes
I would recommend to rest the dough for at least 4 hours.