1In large bowl, mix flour, 1/2 cup sugar, the salt, lemon peel and vanilla bean seeds. Beat in butter with electric mixer on medium speed until mixture looks like small peas. In small bowl, beat egg yolks and 1/4 cup limoncello with whisk. Slowly beat egg mixture into butter mixture. Turn off mixer as soon as dough comes together. Roll into a ball, and wrap in plastic wrap. Refrigerate 1 hour.
2Heat oven to 425°F. On lightly floured work surface, roll dough into circle big enough to fit in 9-inch tart pan. Place in ungreased pan. Bake about 20 minutes or until crust is golden brown. Cool completely.
3To make filling, in large bowl, beat mascarpone, cream, limoncello, sugar, lemon peel, and vanilla bean seeds in electric mixer on medium speed until soft peaks form.
4Spread filling in cooled crust. Arrange raspberries on top. Melt jelly in small microwavable bowl uncovered in 20-second intervals, until it melts completely. Brush jelly over raspberries with pastry brush.