A ring of raspberries not only makes this tart look great, it also adds a contrast of sweet berry flavor to the deep chocolate mousse. Make sure raspberries are at room temperature or the warm glaze will not set properly.
Preheat oven to 350°F. Lightly butter six 3 1/2- to 4-inch-diameter tartlet pans with removable bottoms.
Process pecans and sugar in a food processor until very finely chopped. Add chocolate crumbs and melted butter and pulse until combined. Divide among tartlet pans. Press firmly and evenly in pans.
Bake until crust is set, about 12 minutes. Transfer tart pans to a wire rack and let cool completely.
Bring cream to a simmer in a medium saucepan over medium heat. Remove from heat. Coarsely chop 6 ounces of chocolate and add to warm cream. Let stand until softened, about 3 minutes. Whisk until smooth. Transfer to a heatproof medium bowl. Place in a larger bowl of iced water and let stand, stirring occasionally, until cool and thickened, about 20 minutes. Whisk just until mixture forms soft peaks. Evenly distribute among cooled crusts.
Grate remaining 1 ounce of chocolate on large holes of box grater onto waxed paper. Refrigerate until ready to use. Top each mousse with a circle of raspberries along the outer edge.
Bring preserves and liqueur to a simmer over medium heat, stirring often. Cook until last drops from a wooden spoon are very sticky, about 2 minutes. Strain through a wire sieve into a bowl. Use the glaze immediately.
Immediately brush warm glaze over raspberries using a pastry brush. Let cool for 5 minutes. Using waxed paper as an aide, sprinkle grated chocolate around perimeter of crust. (Do not touch grated chocolate with fingers, or it will melt.) Refrigerate until chilled, at least 1 hour, up to 8 hours. Carefully remove from pans. Serve chilled.
If Making Ahead
The tarts can be refrigerated, uncovered, for up to 1 day ahead.