Prep
Preheat oven to 350°F (175°C).
Line a 12-cup muffin tin with paper liners.
Finely grate carrots and lightly pat dry if very moist.
Mix Dry Ingredients
In a large bowl, whisk together flour, baking soda, baking powder, cinnamon, nutmeg, and salt.
Mix Wet Ingredients
In another bowl, whisk eggs, maple syrup (or honey), oil, Greek yogurt, and vanilla extract until smooth.
Combine
Add wet ingredients to dry ingredients.
Stir gently until just combined.
Fold in grated carrots, nuts, and raisins if using.
Do not overmix.
Bake
Divide batter evenly among muffin cups, filling each about ¾ full.
Bake for 18–22 minutes, until tops are lightly golden and a toothpick inserted comes out clean.
Cool
Let muffins cool in pan for 5 minutes.
Transfer to a wire rack and cool completely before glazing.
Make the Glaze
Beat softened cream cheese and Greek yogurt until smooth.
Add powdered sugar and vanilla.
Mix until creamy.
Add a small splash of milk if needed to reach a drizzle consistency.
Glaze
Drizzle glaze over cooled muffins.
Let set for 10–15 minutes before serving.