Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with paper muffin liners.
Mix the flour, baking powder, baking soda, cinnamon, nutmeg, and salt in a medium bowl. Set aside.
2 ½ cups all-purpose flour, 2 teaspoon baking powder, ½ teaspoon baking soda, 2 teaspoon ground cinnamon, ½ teaspoon ground nutmeg, ½ teaspoon salt
In a large mixing bowl, beat eggs until fluffy and pale in color. Add in the sugar and butter, and continue beating for 1-2 minutes. Next, mix in the buttermilk and vanilla extract.
3 large eggs, 1 cup granulated sugar, ½ cup butter, softened, 1 cup buttermilk, 1 teaspoon vanilla extract
Add in the dry ingredients and mix until just combined, where no flour remains.
Scoop batter into muffin liners, filling about ⅔ full.
Mix the topping ingredients in a small bowl. Scoop a heaping tablespoon onto the top of each muffin.
¼ cup brown sugar, ¼ cup granulated sugar, ½ teaspoon ground cinnamon, ¼ cup chopped pecans or walnuts
Bake for 20-25 minutes, until a toothpick inserted comes out clean.
Notes
For an even more moist muffin try replacing half of the butter with canola or vegetable oil.
Cook miniature muffins for 12-15 minutes, and jumbo muffins for 25-30 minutes.
Store in an airtight container at room temperature for up to 4 days.