How to Make It
Preheat the oven to 400°. Line the bottom and sides of the frozen pastry shell with foil and fill with pie weights or dried beans. Bake for 15 minutes. Remove the foil and weights and bake for about 3 minutes longer to dry out the bottom. Transfer the pan to a rack and let the shell cool to room temperature. Reduce the oven temperature to 350°.
In a small saucepan, melt the butter and honey together over high heat. Add the brown and granulated sugars and stir until dissolved, then boil for 1 minute without stirring. Add 1/3 cup of the heavy cream and stir constantly until smooth. Remove from the heat and stir in the chopped pecans.
Pour the mixture into the baked pastry shell. If necessary, spread the pecans to evenly distribute them over the bottom of the tart. Bake for about 20 minutes, until bubbles appear around the edges and the center is slightly firm. Transfer the tart to a rack to cool.
In a small saucepan, bring the remaining 1/4 cup heavy cream to a boil over high heat. Remove from the heat, add the chocolate and stir until melted. Spread the chocolate evenly over the cooled tart.
Decorate the tart. Cut out an 11-inch circle from a piece of parchment or waxed paper. Fold it in eights, then open it and cut out every other wedge, leaving 4 wedges held together at the center. Place it on top of the tart. Using a fine sieve, dust the cocoa over the exposed tart. Carefully lift the paper and shake off excess cocoa. Set the paper over the cocoa-dusted sections and sift confectioners' sugar over the tart. Carefully remove the paper. Remove the rim of the pan and transfer the tart to a serving platter. Place a cluster of mint sprigs in the center of the tart.