Follow these straightforward steps to create these delightful Carrot Muffins:

1. Preheat the Oven: Set your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it well.
2. Mix Dry Ingredients: In a large bowl, whisk together the all-purpose flour, granulated sugar, brown sugar, baking powder, baking soda, salt, cinnamon, and nutmeg.
3. Combine Wet Ingredients: In another bowl, beat the eggs and then add the vegetable oil and vanilla extract. Mix well until fully combined.
4. Add Carrots: Stir in the grated carrots into the wet mixture, blending the ingredients thoroughly.
5. Combine Mixtures: Make a well in the center of the dry ingredients and pour in the wet mixture. Stir gently until just combined; do not overmix.
6. Add Optional Ingredients: If desired, fold in the chopped walnuts and raisins into the batter.
7. Fill Muffin Tin: Spoon the batter into the prepared muffin tin, filling each cup about two-thirds full.
8. Bake: Place in the preheated oven and bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.
9. Cool Down: After baking, let the muffins cool in the tin for about 10 minutes before transferring them to a wire rack to cool completely.

These steps will guide you seamlessly through the process of making these incredible muffins!