In a large mixing bowl, cream together the room-temperature salted butter and granulated sugar until light and fluffy. Gradually mix in the instant vanilla pudding, followed by the prepared eggnog, eggs, vanilla extract, and rum extract. Beat this mixture until smooth and well combined, about 2-3 minutes.

In a separate bowl, whisk together the all-purpose flour, baking powder, salt, and freshly ground nutmeg until evenly mixed. Gradually add to the wet ingredients, mixing gently until just combined.

Preheat your oven to 350°F (175°C). Grease and flour the mini loaf pans or a single large loaf pan to prevent sticking.

Pour the batter evenly into the prepared pans. For the crumb topping, mix cold, cubed butter, sugar, all-purpose flour, and cinnamon until it resembles coarse crumbs. Sprinkle over the batter.

Bake for 35-40 minutes for mini loaves or up to 70 minutes for a large loaf. The bread is done when a toothpick comes out clean or with a few moist crumbs.

Allow the bread to cool in the pans for about 10 minutes before transferring to a wire rack to cool completely.