1. Make the chocolate cookie dough by whisking flour, cocoa powder, sugar, and salt, then cutting in cold butter until sandy.

2. Add the egg yolk and vanilla, gently bringing the dough together without overworking it.

3. Chill the dough briefly, then roll it out and cut circles slightly larger than your silicone dome molds.

4. Bake the cookie bases until just set, then cool completely on a rack.

5. Bloom the gelatin for the mascarpone mousse in cold water and let it stand for a few minutes.

6. Whip the cold heavy cream to soft peaks, then chill while you whisk mascarpone, powdered sugar, vanilla, and orange zest until smooth.

7. Warm the bloomed gelatin just until melted, whisk it into the mascarpone mixture, then gently fold in the whipped cream.

8. Fill silicone dome molds with the mascarpone mousse, tapping the tray to remove air pockets, and freeze until very firm.

9. Prepare the chocolate mirror glaze by simmering water, sugar, corn syrup, and cream, then whisking in cocoa powder until smooth.

10. Add the bloomed gelatin for the glaze, strain if needed, and cool to about 90 F so it is still pourable but not hot.

11. Unmold the frozen domes onto a wire rack set over a tray and pour the mirror glaze in one smooth motion to coat each dome.

12. Let excess glaze drip off, then carefully transfer each dome onto a chocolate cookie base.

13. Decorate the domes with dark chocolate curls, fresh blackberries, and mint leaves just before serving.

14. Refrigerate the assembled domes until slightly softened but still chilled before presenting.