Combine hazelnuts and gingersnaps with melted butter, sugar, & zest. Press into bottom and sides of six buttered mini-tart pans (4.75” diameter each). Bake in 350 degree oven for 6-7 minutes and cool on rack.
Meanwhile, combine water, sugar, cranberries, ginger, and zest & bring to a boil. Simmer over medium heat for 5 minutes. Take off heat & add limoncello. Cool half the cranberry filling, and puree half the mixture in a blender until smooth.
Whip heavy cream to stiff peaks. In a separate bowl, combine lemon curd, sour cream, and mascarpone cheese until smooth, then fold in whipped cream.
Whip heavy cream until stiff peaks, then add maple syrup and vanilla.
To assemble, spread cranberry sauce on the bottom of each tart shell, then the lemon filling. Remove tarts from pans. Plate cranberry puree and whipped cream on the side. Garnish with candied lemon slices and sugared cranberries (optional).