This tart mingles honey's distinctive sweetness with tart berries and smooth mascarpone cream. Roasting blueberries tossed with honey, lemon, and rosemary kicks up their flavor; layered over honey-infused mascarpone cream, these deeply flavored berries mean business. A simple pat-in-the-pan pine nut crust (inspired by Alice Medrich's foolproof shortbread crust) rounds out the subtle resinous flavor from the rosemary. —Suzanne
To make the crust, mix butter, sugar, salt, pine nuts, and vanilla extract in a medium bowl. Add flour and stir until just blended. Press the dough evenly over the bottom and up the sides of a 9½-inch tart pan with a removable bottom. Generously prick the bottom and sides with the tines of a fork. Bake in the lower third of an oven preheated to 350° F until the crust is pale golden, about 20 to 25 minutes. Cool completely.
To roast blueberries, toss berries with lemon juice, 2 tablespoons of the honey, and rosemary sprigs on a rimmed baking sheet lined with foil. Roast in an oven preheated to 400° F until very tender and just starting to collapse, 10 to 15 minutes. Remove from oven. Discard rosemary sprigs (it's okay if a few leaves remain with the blueberries). Set aside to cool to room temperature.
For the cream filling, whisk together mascarpone, 1/4 cup of the honey, heavy cream, and a pinch of salt in the bowl of a standing electric mixer until smooth and thick, taking care not over-beat. Scrape mixture into the cooled tart crust, spreading it evenly to the edges.
Strain the cooled blueberries over a small bowl. In a separate bowl, toss blueberries gently with reserved lemon zest and a pinch or two of salt.
Top cream-filled tart crust with blueberries and drizzle with remaining honey. Garnish with fresh rosemary sprigs, if desired, and serve with reserved berry juices.