These coffee cake cookies taste *just* like coffee cake! With a crumbly cinnamon streusel topping, vanilla icing, and soft and chewy texture, they're nothing short of addicting.
Brown the butter: Set a small saucepan over medium heat, and melt butter. As it begins to foam and sizzle, stir occasionally with a whisk.About 5 - 7 minutes later, once the foaming subsides, you should see specks of brown milk solids on the bottom of the pan and the butter should be emanating a nutty aroma. Immediately remove the pan from the heat, and transfer to the bowl of a stand mixer. Cool to room temperature.
Mix the dry ingredients: Meanwhile, in a medium bowl, combine 2 ½ cups all-purpose flour, 1 teaspoon ground cinnamon, 1 teaspoon Diamond Crystal Kosher Salt and 1 teaspoon baking soda. Set aside.
Cream the butter and sugar: Fit the paddle attachment to the mixer. Add 1 ½ cups brown sugar to the mixing bowl, and beat on medium speed for 3 - 4 minutes until light and fluffy.
Add the remaining wet ingredients: Add 1 large egg, 1 large egg yolk, and 1 teaspoon vanilla extract to the butter-sugar mixture. Beat on medium speed until fully combined, about 2 - 3 minutes, scraping down the bottom and sides of the bowl with a rubber spatula as needed.
Finish the dough: On low speed, slowly add in the dry ingredients until just barely combined. Cover the dough with plastic wrap and chill in the fridge for 1 hour.
Prepare the Streusel:
In a small bowl, using your hands or a clean fork, combine 2 tablespoons unsalted butter¼ cup all-purpose flour, 3 tablespoons brown sugar½ teaspoon ground cinnamon, and ½ teaspoon Diamond Crystal Kosher Salt until they form crumbs. If it's too sticky, add more flour.Chill for at least 5 minutes in the fridge. Note: You can squeeze together smaller crumbs to make larger crumbs (and vice versa). I like having a mix of smaller and larger crumbs for a nice textural variation.
Portion the Cookies:
Preheat the oven to 350℉/177℃. Line two rimmed baking sheets with parchment paper.
Using a cookie scoop or a large spoon, portion the dough into cookie dough balls that are about 2 tablespoons (1 ¾ inches or 45g) big.
Dip one side of each dough ball into the streusel. Note: If the streusel isn't sticking, you can make a thumbprint in each dough ball, then gently scoop some streusel into the center of the cookie. Pat it gently to stick. Arrange them on the prepared baking sheets, ensuring there's at least 2 inches of space around each cookie.
Bake the Cookies:
Bake for 12 - 14 minutes, or until the edges and the streusel topping are both golden brown.
Remove from the oven and cool on the baking sheet for 3 minutes before transferring to a wire rack to cool completely.
Make the Glaze:
In a small bowl, mix 1 ½ cups powdered sugar, 2 tablespoons milk or cream, and ½ teaspoon vanilla extract until smooth and lump-free.Transfer to a plastic bag or piping bag and snip off the end. Drizzle glaze over cookies and allow to set completely. Top with flaky salt (if using).
Frost and Serve:
Serve cookies, and enjoy!
Notes
Measuring: The best way to accurately measure your ingredients is to use a scale. If using measuring cups, make sure to apply the scoop-and-level method. Use a fork to mix and break up any clumps in the bag of flour, then spoon the flour into a measuring cup; do not pack. Once full, use a knife to cleanly level off any excess flour off the top of the cup. Streusel Tip: If the streusel isn't sticking, you can make a thumbprint in each dough ball, then gently scoop a little bit of filling into the center of each cookie. Pat gently to stick.Storage: Store in an airtight container for up to a week at room temperature.