Decadent Marble Muffins: A Delightful Twist on a Classic Treat

Preparation:
1. In a large bowl, vigorously beat the eggs and sugar until the mixture acquires a whitish color. Add the natural yogurt and mix. Then, add the dry ingredients (flour + baking powder) to the preparation and mix. Finally, add the melted butter.
2. Divide the dough into two different bowls. In one of them, add the cocoa powder and mix well.
3. In the other bowl, add the vanilla and mix well.
4. With the help of some soup spoons, pour the two masses into the muffin mold, alternating them randomly.
5. When all the dough is in the mold, use a wooden skewer or the tip of a knife to mix both masses a little, without overmixing.
6. Preheat the oven to 180°C and bake the muffins for 15 minutes.
7. Once baked, let them cool completely, preferably on a rack.

These marble muffins are perfect for breakfast, brunch, or as a sweet snack throughout the day. Enjoy them with a hot cup of coffee or a cold glass of milk for a delightful treat that everyone will love!