MELT butter in medium saucepan over medium-high. Add pears, currants, brandy, sugar, lemon juice, cardamom and salt. Cook, stirring occasionally, until pears are tender and juices have thickened slightly, 10 to 12 min. Add vanilla and pecans. Cool and refrigerate at least 1 hour, or preferably overnight.
PREHEAT oven to 375 F. Line a large baking sheet with parchment.
PLACE 1 heaping tbsp of filling on each round. Brush edges with egg and fold dough over the filling, forming a half-circle. Press to seal. Crimp edges. Arrange empanadas on their sides on prepared baking sheet. Brush with remaining egg. Sprinkle with coarse sugar.
BAKE until golden brown, 30 to 35 min. Serve dessert empanadas warm or cool with ice cream or crème anglaise, or freeze for up to 2 weeks. Reheat in a 350F oven for 15 min.