½ cup (93 grams) vegetable shortening, plus more for greasing the pan
3 cups (375 grams) all-purpose flour, plus more for dusting the pan
2 sticks (8 ounces/226 grams) unsalted butter, well softened
Scant 3 cups (580 grams) sugar
5 large eggs, at room temperature
2 teaspoons vanilla extract
seeds of 1 vanilla bean (optional)
1 teaspoon kosher salt
3/4 teaspoon baking powder
1 cup whole milk, at room temperature
For the Gingerbread Swirl:
2 cups prepared cake batter
1/4 cup unsulfured molasses
1 1/4 teaspoon ground ginger
1 teaspoon ground cinnamon
1/2 teaspoon ground nutmeg
1/4 teaspoon ground cloves
1/8 teaspoon ground allspice
2 tablespoons melted unsalted butter
1/4 cup granulated sugar mixed with 3/4 teaspoon ground cinnamon
Preheat the oven to 350 degrees; position the rack in the center of the oven.
Thoroughly grease a 9-inch Bundt pan with the shortening, getting into every nook to ensure that the cake releases perfectly from the pan after baking. Dust the pan with the flour and tap out any excess.
Place the shortening in a large bowl and, using an electric hand mixer or stand mixer, beat the shortening until softened and spread around. Add the butter and sugar and beat together on low speed until the mixture looks fluffy, 3 to 5 minutes. (The mixture will seem grainy as it comes together.) Increase the speed to medium and beat the ingredients until well combined, some graininess has softened, and the texture feels more cohesive and almost fluffy, 3 to 5 minutes.
With the mixer running, add the eggs, one at a time, beating for 1 minute between each addition. After the last egg, the batter may look slightly curdled.
Beat in the vanilla extract and seeds of the vanilla bean, if using.
In a medium bowl thoroughly whisk together the flour, salt and baking powder.
Add half of the dry ingredients to the butter and egg mixture. Beat on low speed until just combined and a few flour streaks remain. With the mixer motor running, add the milk and beat until just combined. The mixture may appear curdled again. Add the remaining flour and beat until combined. Using a silicone spatula, scoop batter from the bottom and sides of the bowl to the top for any hidden pockets of flour. Using the hand mixer, beat on medium speed for 1 minute.
Spoon 2 cups of cake batter into a small bowl. Stir in molasses and spices until well combined.
Spoon half of the plain batter into the prepared pan. Add half of the gingerbread batter atop the plain batter and smooth. Add the remaining plain cake batter and the remaining gingerbread batter on top of that. Smooth the top and use a butterknife or offset spatula to dig down into the cake batter layers and swirl slightly. Smooth the top and place on the middle rack in the oven.
Bake for 1 hour and 10 minutes to 1 hour and 20 minutes, until the cake is golden brown, has risen, and cracked across the top. Insert a toothpick to test the doneness of the cake; it should come out clean or with a few moist crumbs. If not, bake the cake for 5 more minutes and test again.
Let the cake cool in the pan on a wire rack for 20 minutes. Run a butterknife around the edges and gently invert the cake on a wire rack to cool completely.
Brush with melted butter and sprinkle generously with cinnamon sugar.
Store, wrapped at room temperature for up to 5 days.