For the crumble
1/2 cup (109 g) packed light brown sugar
4 tablespoons (48 g) non hydrogenated vegetable shortening
1/2 cup (70 g) all-purpose gluten-free flour (I used Better Batter)
1/4 teaspoon xanthan gum (omit if your blend already contains it)
1/8 teaspoon (a pinch) kosher salt
For the muffin batter
1 3/4 cups (245 g) all purpose gluten free flour (I used Better Batter)
1/2 teaspoon xanthan gum (omit if your blend already contains it)
1/4 cup (36 g) cornstarch
1 teaspoon baking powder
1/4 teaspoon baking soda
1/2 teaspoon kosher salt
1/4 teaspoon ground cinnamon
3/4 cup (150 g) granulated sugar
6 tablespoons (84 g) unsalted butter, at room temperature
1 teaspoon pure vanilla extract
2 eggs (100 g, weighed out of shell) at room temperature, beaten
1 cup (8 fluid ounces) buttermilk, at room temperature
In a medium-size bowl, place brown sugar and shortening and mix until creamy and well-combined. Add the flour, xanthan gum, and salt and mix until coarse crumbs form. Place the crumble in the refrigerator to chill while you make the muffin batter.
Preheat your oven to 350°F. Grease or line a standard 12-cup muffin tin and set it aside. In a medium-sized bowl, place the flour, xanthan gum, cornstarch, baking powder, baking soda, salt, and cinnamon, and whisk to combine well. Set the bowl aside.
In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, place the butter and granulated sugar and beat on medium-high speed until very well-combined. Add the vanilla and eggs, and beat until light and fluffy. Add 1/3 of the dry ingredients, and beat to combine. Add half of the buttermilk, and beat to combine. Add half of the remaining dry ingredients and then the remaining buttermilk, beating to combine in between. Add the final dry ingredients and, if using a hand mixer, mix by hand just until combined since the batter will very thick and will climb up the beaters. If using a stand mixer, beat until just combined. Remove the crumble topping from the refrigerator, crumble about 3/4 of the mixture into the batter and fold in with a spatula until the mix-in is evenly distributed throughout the batter. Divide the batter evenly among the 12 prepared muffin cups, and smooth the tops of the batter with wet fingers. Scatter the remaining crumble evenly on top of all of the wells, and press gently to help the crumble adhere to the wet batter.
Place the muffin tin in the center of the preheated oven and bake until the tops of the muffins spring back when pressed gently in the center and a toothpick inserted in the center comes out with no more than a few moist crumbs attached (about 20 minutes). Allow to cool in the muffin tin for 5 minutes before transferring to a wire rack to cool completely.
Originally published on the blog in 2011. Recipe altered to make muffins larger and more tender; all photos and video new.