How to Make It
Preheat the oven to 450°. In a food processor, coarsely chop the almonds with 3 tablespoons of the sugar. Sprinkle half of the nut mixture in the Tart Shell.
Arrange the pear slices in overlapping concentric circles in the Tart Shell and brush them with the marmalade, reserving a scant tablespoon. Sprinkle the remaining nut mixture over the pears.
Reduce the oven temperature to 400°. Bake the tart in the bottom third of the oven for about 1 hour, or until the pears are tender and the pastry is golden. Transfer to a rack and brush the pastry rim with the reserved marmalade. Let cool. Stir the remaining 1 tablespoon sugar into the sour cream and serve with the tart.