Brown Butter Pumpkin Vanilla Crumb Cake

Brown the butter for the cake batter in a light colored saucepan over medium heat. Stir often as it foams, sizzles, and then quiets. Cook until golden brown specks form on the bottom and the butter smells nutty. Remove from heat and pour into a heatproof bowl to cool for 15 minutes until it's cool to touch. In the same pan brown the butter for the crumb topping.

In a medium bowl, whisk together the brown sugar, flour, cinnamon, vanilla bean powder, and salt. Pour in the browned butter and stir with a fork or rubber spatula until no dry flour remains. The mixture should resemble damp sand and hold together when squeezed. Use your fingers to press the mixture into large and small clumps. Refrigerate the crumb topping while preparing the pumpkin coffee cake batter.‍

While the streusel is chilling, preheat your oven to 350°F (175°C) and line an 9-inch circle or 9X9 square pan with parchment paper, leaving overhang on two sides for easy lifting.‍

In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, cloves, and allspice. Whisk well so the leavening and warm spices are distributed evenly throughout the dry ingredients and set aside. ‍

Add the granulated sugar and light brown sugar to the bowl containing the cooled brown butter. Whisk until thoroughly combined. Add the eggs one at a time, whisking well after each addition. Whisk in the vanilla extract, pumpkin puree, and sour cream until the wet ingredients are smooth and evenly combined.‍

Add the dry ingredients to the wet ingredients. Use a rubber spatula to fold the mixture together just until no dry streaks of flour remain. The batter will be thick. Do not overmix, or the cake may develop a dense or rubbery texture. Spread the pumpkin coffee cake batter evenly into the prepared pan. Smooth the top of the batter with an offset spatula or the back of a spoon.

Remove the chilled crumb topping from the refrigerator. Break it into a mixture of small and large pieces, with some crumbs approximately the size of peas and others closer to the size of almonds or small walnuts. Scatter all of the crumbs evenly over the top of the cake. Do not place half of the crumbs inside the batter. Keeping the entire crumble layer on top gives the cake better structure. ‍

Bake the cake on the center rack for 55 to 65 minutes. Begin checking it at approximately 52 minutes. If the crumb topping becomes too dark before the center is done, loosely tent the pan with aluminum foil. The cake is ready when the center appears set and no longer looks wet. The cake springs back lightly when touched. A toothpick inserted into the center comes out with a few moist crumbs but no wet batter. If using an oven thermometer, the internal temperature near the center reaches approximately 200°F to 205°F.‍

Place the pan on a wire rack and let the cake cool in the pan for at least 30 minutes. For cleaner individual slices, allow the cake to cool completely before lifting it from the pan using the parchment paper.‍

Add the powdered sugar, vanilla bean paste, salt, and 1½ tablespoons of milk or heavy cream to a small bowl. Whisk until smooth. Add more milk or cream, 1 teaspoon at a time, until the glaze is thick but pourable. Drizzle the glaze over the cooled cake. Allow it to set for approximately 15 minutes before slicing.