5tablespoons (71g)unsalted buttermelted and cooled to room temperature
For the coffee cake:
1 ½cups (222g)gluten free flour blend
1teaspoonbaking powder
½teaspoonbaking soda
½teaspoonfine sea salt
½cup (113g)unsalted butterroom temperature
⅔cup (133g)granulated sugar
½cup (114g)Greek yogurtroom temperature
½cup (120ml)whole milkroom temperature
1teaspoonvanilla extract
Instructions
To make the streusel topping, combine the flour, both sugars, cinnamon, and salt in a medium bowl. Add in the melted butter and stir well to combine. The entire mixture should be moist.
¾ cup (111g) gluten free flour blend, ½ cup (100g) granulated sugar, ½ cup (100g) light brown sugar, ½ tablespoon cinnamon, ¼ teaspoon fine sea salt, 5 tablespoons (71g) unsalted butter
Preheat the oven to 350°F. Grease an 8" square baking pan and set aside.
In a medium bowl, whisk the flour, baking powder, baking soda, and salt together. Set aside.
1 ½ cups (222g) gluten free flour blend, 1 teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon fine sea salt
Using a hand mixer or a stand mixer fitted with the paddle attachment, cream the butter with the sugar until smooth.
½ cup (113g) unsalted butter, ⅔ cup (133g) granulated sugar
Add the yogurt, milk, and vanilla extract and beat to incorporate. Add the dry ingredients to the wet ingredients and mix on low speed until combined.
½ cup (114g) Greek yogurt, ½ cup (120ml) whole milk, 1 teaspoon vanilla extract
Transfer the batter to the prepared baking pan and use a rubber spatula to smooth into an even layer. Sprinkle the streusel on top. Bake for 38-40 minutes, or until a toothpick inserted into the center comes out clean. Allow the cake to cool for at least 15 minutes before serving.