Day 1 – Soak the Fruit: In a medium bowl, combine the raisins, orange peel, and lemon peel. Pour in the rum or juice, cover, and let it sit at room temperature for 12 to 16 hours.
Day 2 – Make the Dough: Prepare the babka dough. After mixing, stir in lemon zest, vanilla, cardamom, cinnamon, and nutmeg. Drain the soaked fruit (reserving the liquid if desired). Gently fold in the fruit and toasted almonds and mix until evenly distributed.
First Rise: Cover the dough and let it rise for about 1 hour, until slightly puffy.
Prepare Filling: While dough rises, shape the almond paste into two 8-inch logs (about 2 ounces each). Cover to keep from drying out.
Divide and Preshape: Turn dough onto a lightly floured surface. Divide into two equal portions (~19 oz each). Lightly shape each into a log and rest for 15 minutes.
Shape the Stollen: With a rolling pin, flatten each dough piece into a rectangle, pressing a slight trough down the center. Place an almond paste log into the trough. Fold and seal the dough around it, creating a slightly humped shape typical of stollen.
Final Rise: Transfer shaped loaves onto a parchment-lined baking sheet, seam-side down. Let rise for 45 to 60 minutes until puffy. Meanwhile, preheat oven to 350°F.
Bake: Bake until deep golden brown and internal temperature hits 200°F—about 35 minutes.
Finish: While hot, brush loaves with melted butter and coat with granulated sugar. Cool completely on a rack.
Dust and Store: After cooling, coat generously with confectioners’ sugar. Store tightly wrapped at room temp for up to 1 week. If freezing, wait to dust until thawed and ready to serve.