Preheat the oven to 325 degrees F. Spray a 15-cup bundt pan with with nonstick baking spray OR use a pastry brush to coat the pan in butter and add 2-3 tbsp of flour. Coat the entire pan in the flour and tap off any excess flour. Set aside.

Start by mixing the dry ingredients - In a separate bowl, add cake flour, nutmeg, cardamom, and kosher salt together in a bowl. Whisk together and set aside.

Add butter, butter flavored shortening, and sugar to the bowl of a stand mixer fitted with the paddle attachment. Mix on medium speed for 7 minutes, scraping down the sides of the bowl midway through. Begin adding eggs, one at a time, ensuring that each egg is fully incorporated prior to adding the next. Then add in the vanilla extract and butter vanilla emulsion. Scrape down the sides of the bowl again and continue to mix for 1-2 minutes, until all ingredients are fully incorporated and the mixture looks fluffy.

Add half of the flour mixture to the bowl, mix until just combined, about 15 seconds. Then pour in the buttermilk and continue to mix on low speed until combined, about 10 seconds. Add the remainder of the dry ingredients and mix until combined, about 20 seconds.

Scrape down the sides of the bowl once more, ensuring to scrape all of the way down to the bottom of the bowl, making sure that all of the batter is mixed together.

Add the cake batter to the prepared bundt pan. Bake for 1 hour and 25-35 minutes, until a skewer inserted into the center of the cake comes out clean. Allow the cake to cool in the pan for 10 minutes, then turn over to cool completely on a wire rack.

Once the cake has cooled, make the powdered sugar glaze by mixing together powdered sugar, buttermilk, sour cream, vanilla extract, a pinch of salt, and the tiniest dash of cardamom. Pour on top of the cake and serve.