1. Combine raisins, currants, citrus peel, angelica, and cherries in a bowl. Add the rum, tossing to coat fruits evenly. Soak at least 1 hour, stirring occasionally.

2. Pour water into a small bowl; sprinkle with yeast and a pinch of sugar. Let stand 2 to 3 minutes; stir to dissolve yeast completely. Set aside until mixture almost doubles in bulk, about 5 minutes. Meanwhile, drain fruit, reserving rum; carefully pat fruit dry with a paper towel. Return fruit to bowl; add almonds. Sprinkle with 2 tablespoons flour. Toss; coat evenly. Set aside.

3. In a heavy saucepan, combine 1 cup milk, 3/4 cup granulated sugar, and salt. Heat until warm (110 to 115 degrees), stirring until sugar is dissolved. Transfer liquid to bowl of an electric mixer fitted with the paddle attachment; add reserved rum, almond extract, and lemon zest. Stir to combine. Stir in yeast mixture and eggs. Gradually add 5 cups flour, 1 cup at a time; beat until combined. Beat in softened butter until well incorporated. Turn dough out onto a surface floured with remaining 1/2 cup flour. Knead dough until all the flour is incorporated and dough is smooth and elastic, about 5 minutes. Flour hands if dough gets sticky. Knead in one-third of the dried-fruit mixture until incorporated. Brush a large bowl with 1 teaspoon melted butter; drop in dough. Brush top of dough with 2 teaspoons melted butter; drape a kitchen towel over bowl. Set in a warm, draft-free place to rise until doubled in bulk, about 2 hours.

4. Preheat oven to 375 degrees. Line a baking sheet with parchment; set aside. Punch dough down; roll into a rectangle about 16 by 24 inches and 1/4 inch thick. Sprinkle remaining fruit over pastry. Starting with a long side, roll up tightly, forming a long, thin cylinder. Carefully transfer dough to baking sheet; join ends together, pinching with fingers if necessary to make it stick, forming a large circle.

5. Using sharp kitchen scissors, make cuts along outside of circle, in 2-inch intervals, cutting two-thirds of the way through the dough. Twist each segment outward, forming a wreath shape with all segments overlapping. Brush dough with remaining 2 tablespoons melted butter.

6. Cover pastry with a clean kitchen towel; set aside to rise for 30 minutes. Dough will rise only a little bit. Bake until golden brown and crusty, about 45 minutes, rotating halfway through. Place baking sheet on a wire rack to cool before icing.

7. Whisk confectioners' sugar and 2 tablespoons milk to combine. Drizzle over cooled stollen.