MAKE THE CRUST: Combine the flour, butter, eggs, milk and vanilla in the bowl of a food processor fitted with a steel chopping blade. With an on-off motion, process until the butter is the size of small peas. Add the sugar, salt and almonds and process just until the dough starts to pull together. Do not overprocess. Remove the dough from the bowl, pat it into a ball, then flatten it into a disk about 3/4-inch thick, and dust with flour. Cover with plastic wrap and refrigerate for at least 1 hour. Preheat oven to 375F. Remove the dough from the refrigerator and gently massage it until it is workable, turning it over a couple of times, and starting to flatten it with your fingertips. Dust the dough, rolling pin and board or pastry cloth with flour, and quickly roll dough into a rectangle large enough to fit into an 11-by-17-inch jelly roll pan and about 1/8-inch thick. If the dough sticks, add small amounts of flour and loosen with a dough scraper or long, thin-bladed knife. Carefully roll the dough over the pin or fold it into quarters and position it over the pan. Unroll, and ease the dough into the tart pan, working to flatten the bottom and to ease the dough well into the corners and against the sides. Patch where necessary, then trim off any excess dough with a knife. Prick in several places, and transfer the pan to the middle of the preheated oven to bake just until the pastry is set but not browned, about 8 to 10 minutes. Remove the pan and let the pastry cool while preparing the filling. FILL THE TART: In a medium-size bowl, combine the almond paste, eggs and amaretto, beating with an electric mixer until smooth. Scrape the mixture into the crust, and spread it evenly with a metal spatula. With a sharp, thin-bladed knife, cut across each pear half at 1/4-inch intervals. You should end up with about 7 slices. Beginning at the left edge of 1 long side, place the wide end of the pear touching the side of the pan, pressing gently to elongate it. Put an apricot half at the narrow end. Next, place an apricot touching the side of the pan, to the right of the first pear, and add a sliced pear with the narrow end touching the apricot. Continue until the whole side is filled with 7 pear halves and 7 apricot halves. Repeat the same procedure for the second half of the tart, continuing with the pears facing in the same direction as they do in the first row. Return the pan to the oven, and bake until the almond paste is light brown and the crust is a rich brown, about 15 to 18 minutes. While the tart is baking, melt the jelly over low heat. Remove the baked tart, brush on the jelly glaze, and let the tart cool to room temperature. Cut the tart into serving size portions of an apricot and pear on each slice. Combine the yogurt with the sour cream and spoon it over the tart as it is served.