Melt butter; stir in sugar. Add crushed crackers; toss to mix well. Spread evenly into Fluted Pie Mold (or similar). Press onto bottom and up sides to form a firm, even crust. Bake at 375°F degrees for 4-5 minutes or til edge is lightly browned. Cool on Floral Cooling Rack.
In Stainless Mixing Bowl, stir together cheese and 6T. of lemon curd until smooth. Spread mixture in bottom of cooled tart shell. In medium bowl, gently stir the blueberries and remaining 4 tbsp lemon curd until thoroughly combined. Spoon the blueberries evenly over the mascarpone layer. Cover and chill 2 hours.
While supporting the bottom of the tart, peel off Pie Mold and place on Vintage Cake Plate to serve. Garnish with fresh blueberries if desired.