Make the Pastry:
Pulse flour, powdered sugar, and salt in a food processor to combine. Add cold butter cubes and pulse until mixture resembles coarse breadcrumbs with some pea-sized pieces remaining.

Whisk egg yolk with 2 tablespoons ice water and vanilla. Add to processor and pulse just until dough begins to clump together. Add remaining tablespoon water only if needed.

Turn dough onto a lightly floured surface and bring together into a disc. Wrap tightly in plastic and refrigerate at least 30 minutes.

Make the Tropical Mincemeat:
Combine fresh mango, papaya, pineapple, golden raisins, dried mango, lime zest and juice, orange zest and juice, brown sugar, butter, and all spices in a medium saucepan.

Cook over medium heat, stirring occasionally, until fruits soften and liquid reduces to a jammy consistency, 15-20 minutes. The mixture should be thick and glossy, not watery.

Remove from heat, stir in rum and coconut oil if using. Cool completely—the mincemeat will thicken further as it cools. Can be made up to 1 week ahead.

Make the Crumble Topping:
Combine flour, butter, demerara sugar, coconut, and salt in a bowl. Rub butter into dry ingredients with fingertips until mixture forms clumps of varying sizes. This is a restrained crumble—just enough to add texture without overwhelming the fruit filling. Refrigerate until needed.

Make the Holly Leaves:
Knead a small amount of green gel food coloring into reserved pastry scraps until evenly colored.

Roll green pastry to ⅛-inch thickness. Using a small holly leaf cutter (or cutting freehand with a sharp knife), cut 24-36 leaves. Use the back of a knife to score vein lines.

Place leaves on a parchment-lined baking sheet, curving some gently over a wooden spoon handle for dimension. Refrigerate until firm.

Assemble the Pies:
Preheat oven to 375°F (190°C). Lightly grease a 12-cup muffin tin.

Roll remaining pastry to ⅛-inch thickness. Using a 3½-inch round cutter, cut 12 circles. Gently press each into a muffin cup, ensuring pastry comes up the sides without stretching. Prick bases lightly with a fork.

Spoon 1½ tablespoons tropical mincemeat into each pastry case—fill generously but leave room for crumble.

Sprinkle a scant tablespoon of crumble topping over each pie. Restraint is key here; the crumble should accent, not blanket, the filling.

Bake:
Bake pies 20-22 minutes until pastry is golden and crumble is lightly browned.

Meanwhile, place holly leaves on a separate baking sheet. Brush lightly with egg white and bake 6-8 minutes until just set and slightly darker green. Watch carefully—they color quickly.

Cool pies in tin 10 minutes, then carefully transfer to a wire rack.

Decorate:
Arrange 2-3 holly leaves on each cooled pie, clustered to one side. Add fresh cranberries or red fondant balls as berries.

Dust lightly with powdered sugar to mimic snow.