Position rack in lower third of oven. Heat oven to 350 degrees F. Butter insides and rims of 6 large muffin cups. Melt 1/4 cup unsalted butter in small saucepan. Measure 1/4 cup sugar.
Stack flat on top of each other and cover with plastic wrap and damp towel to prevent drying out 4 sheets phyllo dough. Place 1 sheet of phyllo on work surface. Brush sheet with one-fourth of the melted butter and sprinkle 1 tablespoon of the sugar evenly over it. Cover with second sheet of phyllo; butter it and sprinkle with sugar in same manner. Repeat until all 4 sheets of phyllo have been used, ending with layer of butter and sugar. Cut stack of phyllo sheets into 12 square stacks, 4-1/2 inches per side (4 strips lengthwise, 3 widthwise). Place 1 square stack in a muffin cup; ease it in with backs of fingers so it covers half the bottom and rises to hang over side of cup. Ease in second stack, slightly overlapping the first to cover the other half of muffin cup. Repeat to make 5 more phyllo cups. Bake until pastry is golden brown, 10 to 15 minutes. Let cool completely, then remove phyllo from cups.
Whip together in bowl until almost stiff heavy cream, sour cream, 2 tablespoons sugar, and vanilla.
Fold in shelled pistachios, toasted and chopped.
Just before serving, place a phyllo cup on each of 6 plates. Divide cream among cups. Divide and top with fresh raspberries. Serve immediately. Makes 6 servings.