Step 1

Preheat your oven to 350°F. Grease or line the wells of a standard 12-cup muffin tin and set it aside.

Step 2

If you’d like to add the crumble to the tops of your muffins, make the crumble now. Place all the (optional) crumble ingredients in a small bowl and mix to combine fully.

Step 3

Place the crumble mixture in the refrigerator to chill while you make the muffin batter.

Step 4

In a medium-size bowl, place the eggs, buttermilk, butter and vanilla, and mix until well-combined. Set the wet ingredients aside briefly.

Step 5

In a large bowl, place the flour, xanthan gum, baking powder, baking soda, salt, granulated sugar and brown sugar. Whisk to combine and break up any lumps in the brown sugar.

Step 6

Create a well in the center of the dry ingredients and add the egg and buttermilk mixture. Stir the wet ingredients into the dry ingredients until just combined. Don’t overmix.

Step 7

If adding any simple mix-ins like chocolate chips, add them to the batter now and mix just until evenly distributed throughout the batter.

Step 8

Fill the prepared wells of the muffin tin with batter, and smooth the tops with wet fingers. You should get 12 muffins, but if your wells are deeper than mine you'll get less and more shallow you'll get more.

Step 9

If you’re adding the crumble, remove the bowl from the refrigerator and break up the crumble into irregular pieces (none too large) with the tines of a fork.

Step 10

Sprinkle the crumble generously on the top of the muffin batter in the wells, and press to adhere the mixture to the muffin batter.

Step 11

Place the pan in the center of the preheated oven and bake until the top of the center muffin springs back when pressed gently in the center, about 20 minutes.

Step 12

If you’ve added the crumble, those muffins may take another minute or so to bake fully. Remove from the oven and allow the muffins to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.