Kick off your Cinnamon Swirl Eggnog Bread by preheating the oven to 350°F.
Grease a 9×5-inch loaf pan generously with butter or nonstick cooking spray, then set it aside.
In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, and nutmeg until well combined. Set this dry mixture aside.In a large mixing bowl (or the bowl of a stand mixer), add the softened butter and granulated sugar.
Cream them together on medium speed until light and fluffy, about 2-3 minutes—this step helps create that tender, moist texture we love in quick breads!
Next, add the eggs one at a time to the creamed butter-sugar mixture, beating well after each addition until fully incorporated and the batter looks smooth and fluffy.
Scrape down the sides of the bowl as needed, then add half of the reserved flour mixture.
Beat on low speed just until combined—avoid over mixing to keep the bread tender. This gradual addition helps create that perfect moist crumb!
Now add the eggnog along with the dark rum (or rum extract for a non-alcoholic version) to the batter.
Beat on medium speed until fully incorporated and the mixture is smooth.
Finally, add the remaining flour mixture and beat on low speed just until combined—stop as soon as no dry streaks or patches remain. Be careful not to over mix at this stage, as it keeps the bread beautifully tender and moist!
Spoon or pour approximately half of the prepared batter into your greased loaf pan, spreading it out gently with a spatula to create an even layer that covers the bottom completely. This sets the foundation for that beautiful cinnamon swirl in the middle!
In a small bowl, prepare the cinnamon swirl filling by combining the brown sugar, ground cinnamon, and a pinch of nutmeg (if desired).
Stir everything together thoroughly with a fork or small whisk until evenly mixed and no streaks remain—this fragrant mixture will create that gorgeous, flavorful ribbon throughout your eggnog bread!
Evenly sprinkle the entire cinnamon-sugar mixture over the batter in the loaf pan, covering it from edge to edge for a consistent swirl.
Then, take a butter knife, skewer, or the handle of a spoon and gently drag it through the batter in a swirling figure-8 or zigzag pattern, pressing down about 1 to 2 inches deep. This helps distribute the cinnamon filling beautifully without fully mixing it in—creating those stunning marbled ribbons when sliced!
Carefully spoon or pour the remaining batter over the cinnamon swirl layer, then use a spatula to gently spread it evenly to the edges, fully covering the filling for a beautiful hidden ribbon.
Place the loaf pan in your preheated 350°F oven and bake for 45-55 minutes, or until a toothpick inserted into the center comes out clean (a few moist crumbs are okay).
Keep an eye on the top—if it begins to brown too quickly before the bread is fully baked, loosely tent the pan with aluminum foil for the remaining time. This simple trick ensures a perfectly golden crust and a moist, tender interior every time!
Remove from oven when a toothpick inserted in center comes out clean. Turn upside down on a wire rack and remove the pan. Flip the bread over and allow it to cool completely before adding the rum glaze for cake.