1ouncebittersweet chocolate, melted, for design, optional
Place the white chocolate in a medium bowl. Pour ¾cup of the cream into a small saucepan and bring to a boil over medium heat. Pour the hot cream all at once on top of the white chocolate. Let sit for 1 minute, then whisk until smooth. Strain into a small bowl, cover with plastic wrap, and puncture several holes in it with the tip of a paring knife. Refrigerate for at least 4 hours, or overnight. Repeat the same procedure with the bittersweet chocolate and the remaining ⅔cup cream, and refrigerate for at least 4 hours, or overnight.
Divide the chopped cherries evenly among the tarts, spreading them on the bottom of each tart.
Scrape the chilled white chocolate cream into a mixing bowl. Using a hand-held mixer, beat at medium speed until medium peaks form. Spoon the white chocolate cream into one half of each tart shell. Beat the bittersweet chocolate cream, and fill the other halves of the shells. Gently shake the tarts to level the tops. Refrigerate for 15 minutes, or until set.
Arrange 5 cherries on each tart. If desired, fill a small paper pastry bag with the melted chocolate, and place a single dot on each tart. Serve.