Step 1 In the bowl of a standing mixer, beat the butter, vanilla bean seeds and 1 cup sugar, about 2 minutes. Scrape down the sides of the bowl if necessary. Beat in the milk and eggs one at a time; mix well.
Step 2 Sift together the flour, baking powder, salt and cardamom into a large bowl. Add to the butter mixture, beating until just incorporated. Cover the bowl with plastic film and chill 2 to 3 hours, until dough is firm.
Step 3For the filling, mix the raisins, one-third cup sugar, lemon zest, lemon juice and ginger in a small saucepan. Stir together the cornstarch and one-half cup water until smooth and add this to the raisin mixture. Heat, stirring occasionally, to boiling. Reduce the heat and simmer, stirring, 4 to 5 minutes. Remove from the heat and cool to room temperature.
Step 4Heat the oven to 400 degrees. Cut the dough in half and roll out two rectangles one-eighth-inch thick. In a small bowl, beat together the egg yolks and cream with a fork. Lightly brush one rectangle of dough with the egg yolk mixture.
Step 5Spoon 12 mounds, about a tablespoon each, of the raisin mixture spread 3 1/2 inches apart on the sheet of dough. Cover with the other sheet of dough and cut around the mound of filling with a fluted round 3-inch cookie cutter. Rework the excess dough, re-roll, fill and cut for the remainder of the cookies. Lift filled cookies onto a parchment-lined baking sheet. Brush the tops of the cookies with the egg yolk mixture and sprinkle with coarse sugar. Bake until golden brown, 10 to 12 minutes.