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. Add egg yolk and 1 tablespoon ice water. Pulse until dough just begins to clump. Add more water only if needed. Turn onto a work surface, press into a disc, wrap tightly, and refrigerate at least 1 hour. Roll pastry to ⅛-inch thickness. Cut six circles and press into 4-inch tart pans with removable bottoms. Trim excess. Prick bottoms with a fork. Refrigerate 30 minutes. Meanwhile, preheat oven to 375°F. Line each tart with parchment and fill with pie weights. Blind bake 15 minutes. Remove weights and bake 5-7 minutes more until light golden and dry. Cool completely.

Prepare the Blackberries:
Toss blackberries gently with sugar and lemon juice. Let macerate 15 minutes while you prepare the frangipane.

Make the Frangipane:
Whisk together almond flour and all-purpose flour in a small bowl. In a stand mixer with paddle attachment, cream butter and sugar until light and fluffy, 3-4 minutes. Add eggs one at a time, beating well after each addition. Add almond extract, vanilla, lemon zest, and salt. Mix until combined. Fold in flour mixture on low speed until just combined. Do not overmix.

Assemble and Bake the Frangipane Layer:
Reduce oven to 350°F. Spoon frangipane generously into each tart shell, filling about two-thirds full. The frangipane layer should be substantial; this is where Dylan's version fell short. Drain macerated blackberries briefly. Nestle 4-5 blackberries into the frangipane in each tart, pressing them gently so they are partially submerged but still visible. Bake 22-25 minutes until frangipane is golden, puffed, and set; a toothpick should come out clean. The frangipane will sink slightly as it cools. Cool completely in pans before adding ganache.

Make the Coffee Gel:
Sprinkle gelatin over cold water in a small bowl. Let bloom 5 minutes. Heat espresso and sugar in a small saucepan until sugar dissolves and liquid is steaming, not boiling. Remove from heat. Whisk in bloomed gelatin until completely dissolved. Pour into a shallow container. Refrigerate until set, about 2 hours. Once set, use a fork to break gel into small, glossy pieces; it should be soft-set and slightly jiggly, not rubbery.

Make the Fruity Chocolate Ganache:
Place chopped chocolate in a heatproof bowl. Heat cream until just simmering. Pour over chocolate. Let stand 2 minutes. Whisk from center outward until smooth and glossy. Whisk in butter and jam until incorporated. Let ganache cool until slightly thickened but still pourable, about 15 minutes. The ganache layer should be thin, just enough to gloss the top, not a thick blanket that overwhelms the frangipane beneath.

Final Assembly:
Carefully remove cooled tarts from pans. Spoon a thin layer of ganache over each tart, tilting gently to spread evenly. Use only 1-2 tablespoons per tart; restraint is key. Before ganache sets completely, place small spoonfuls of coffee gel on top in an attractive pattern, 3-4 small quenelles or dots per tart. Garnish with fresh blackberries, mint leaves, and gold leaf if using. Dust edges of plate with cocoa powder. Let tarts set at room temperature 15 minutes before serving.