Begin by preparing your browned butter. Add the unsalted butter to a medium saucepan set over medium heat. Allow the butter to melt completely, stirring occasionally. As it cooks, keep a close eye on it; you want to remove it from the heat once it starts to turn a golden brown color and develop a nutty aroma. This step is key for infusing your cake with a rich flavor.
Once your browned butter is ready, pour it into a large bowl and let it cool in the refrigerator until creamy and nearly set. This should take about 2 hours. Alternatively, you can chill it overnight, but let it rest at room temperature for about 20 to 30 minutes before using it so that it softens up again.
Now it’s time to preheat your oven to 350 degrees Fahrenheit. Prepare two 9-inch cake pans by buttering them well, lining the bottoms with parchment paper, buttering the parchment, and lightly dusting the pans with all-purpose flour. This ensures that your cakes will release easily after baking.
In a medium mixing bowl, combine 2 1/4 cups of all-purpose flour, 1 teaspoon of baking powder, 1 teaspoon of baking soda, 1/2 teaspoon of salt, 1 1/2 teaspoons of ground cinnamon, 3/4 teaspoon of ground ginger, 1/4 teaspoon of ground nutmeg, and 1/4 teaspoon of ground cloves. Whisk these dry ingredients together for about 20 seconds to combine well.
In the bowl of your electric mixer fitted with the paddle attachment, whip together the cooled browned butter with 1 1/2 cups of granulated sugar until the mixture becomes pale and fluffy. This may take a few minutes, so be patient! Once fluffy, mix in the eggs one at a time, adding 1 teaspoon of vanilla extract with the last egg. Ensure everything is thoroughly combined.
In a separate bowl or liquid measuring cup, mix together 1 2/3 cups of canned pumpkin puree and 1/4 cup of buttermilk. With the mixer set to low speed, add 1/3 of the flour mixture to the butter mixture, mixing just until combined. Then add 1/2 of the pumpkin mixture, mixing just until combined again. Repeat this process, alternating between the remaining flour and pumpkin mixtures, finishing with the last 1/3 of the flour mixture until nearly combined.
Use a spatula to fold the batter gently to ensure everything is evenly incorporated. Divide the batter between the two prepared cake pans, spreading it into an even layer. Bake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean.
While the cakes are baking, prepare the caramel sauce. Gather all caramel ingredients and in a medium saucepan, combine 1 cup of granulated sugar, 1/4 cup of water, and 3/4 teaspoon of fine sea salt. Set the saucepan over medium-high heat and whisk constantly until it begins to boil. Allow the mixture to boil until it turns a rich amber color, swirling the pan occasionally for even cooking.
Once it reaches the desired color, immediately whisk in 1/4 cup of unsalted butter and remove from heat. Carefully whisk in 2/3 cup of heavy cream (it will steam), stirring until smooth. Set the caramel aside to cool for a few minutes and then pour it into a glass bowl or jar. Chill the caramel until cooled completely.
To make the frosting, whip 3/4 cup of unsalted butter until light and fluffy. Gradually add 3 1/4 cups of powdered sugar, 1/2 cup of the cooled caramel sauce, 1/4 teaspoon of fine sea salt, and 1 teaspoon of vanilla extract. Mix until well combined and fluffy. If needed, chill the frosting until it firms up a bit.
Once the cakes are fully baked and cooled, spread the frosting generously over the top of one layer, drizzle some of the remaining caramel sauce over it, and then place the second layer on top. Finish with more frosting and a delightful drizzle of caramel, sprinkling chopped pecans on top if desired. Slice and enjoy your Browned Butter Pumpkin Cake!
