• 1-3/4 cups all-purpose gluten-free flour (use your favorite blend, or my go-to blend: 1 cup superfine brown or white rice flour plus 6 tablespoons potato starch plus 4 tablespoons tapioca flour/starch)
• 1/2 teaspoon xanthan gum (omit if your blend already contains it)
• 1-1/2 teaspoons baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon kosher salt
• 1 teaspoon ground cinnamon
• 1/2 cup sugar
• 8 tablespoons unsalted butter, at room temperature
• 1/4 cup sour cream (or plain whole milk yogurt), at room temperature
• 2 large eggs at room temperature, beaten
• 1 teaspoon pure vanilla extract
• 3/4 cup apple cider, at room temperature (can use an equal amount of apple juice)

• Preheat your oven to 350 degrees F. Grease or line a standard 12-cup muffin tin and set it aside.
• First, make the muffin batter. In a large bowl, place the flour blend, xanthan gum, baking powder, baking soda, salt, cinnamon and sugar, and whisk to combine well. Set the bowl aside. In a separate, smaller bowl, place the butter and sour cream, and beat vigorously until light and fluffy. Add the eggs and vanilla, and beat again until well-combined. Create a well in the center of the dry ingredients, and add the butter and sour cream mixture and the apple cider, alternating between the two and mixing well in between additions. The muffin batter should be thick, but light and fluffy.
• Scoop or pour the muffin batter into the prepared wells of the muffin tin, filling each well about 3/4  full. Shake the tin back and forth to evenly distribute the muffin batter in each well, and set the muffin tin aside.
• In a small bowl, make the topping. Place the sliced apples, cinnamon and sugar in the bowl, and toss to coat the apples well in the cinnamon sugar. Place 5 to 6 thinly sliced apples on top of the batter in each well of the muffin tin. Press down gently and evenly.
• Place the muffin tin in the center of the preheated oven and bake until the apples are soft, the muffins are very lightly golden brown and a toothpick inserted in the center of a muffin comes out mostly clean, with a few moist crumbs attached (about 20 minutes). Allow to cool in the muffin tin for at least 5 minutes before serving. Repeat with the remaining muffin batter. Freeze any completely cooled, leftover muffins.

Sourse : Sheknows