Preheat oven to 350F with rack on lower middle.Roll out crescent dough to about 8.5 inches by 12 inches, with seams closed in. Cut dough into about 40 small 1" squares (actual count may vary a bit; a pizza slicer works well.) Press squares firmly into the bottom and corners of a nonstick mini muffin pan. Bake 8-9 min or until edges are golden brown and puffy.Remove crusts and place on serving platter. Immediately place brie cubes in center of warm crusts. Top with a spoonful of cranberry sauce, followed by a sprinkle of pistachios.Serve immediately and keep any extras on a tray in the warm oven (be careful that oven is not actually hot enough to burn them.) Best served slightly warm.