Preheat oven to 375°F. Line rimmedbaking sheet with parchment paper.
Placepumpkin, cut side down, on parchment.
Bake until very tender, about 1 hour. Cool.
Scoop pumpkin flesh into processor;discard skin.
Combine cinnamon, ginger,and 1/4 teaspoon nutmeg in small bowl.
Addhalf of cinnamon mixture to pumpkin inprocessor.
Add brown sugar, eggs, milk,cream, cornstarch, vanilla, and salt. Processuntil very smooth. DO AHEAD: Filling can bemade 1 day ahead.
Transfer to large bowl,cover, and chill.
Increase oven temperature to 425°F.Lightly butter 9-inch-diameter tart pan withremovable bottom.
Place rimmed bakingsheet in oven to heat. Stir 2 tablespoonssugar into remaining cinnamon mixture.
Lay 1 phyllo sheet on clean work surfaceand brush lightly with butter (keep remainingphyllo sheets covered with plastic wrap anddamp towel to prevent drying).
Sprinkle 1scant teaspoonful cinnamon mixture overphyllo. Repeat 4 times with phyllo, butter, andcinnamon mixture. Arrange stacked phylloin tart pan, gently pressing and allowinglong sides to hang over edge of pan. Repeatlayering process with 5 remaining phyllosheets. Arrange stacked phyllo crosswise atopfirst sheets so that overhanging corners pointin opposite directions.
Roll overhang in to formedge of crust.
Pour pumpkin into pan.
Place pie on hot baking sheet and bake10 minutes. Reduce oven temperature to375°F and bake until tester inserted intocenter of filling comes out clean, 40 to 45minutes. Cool at least 20 minutes. Gratenutmeg over and serve warm.
Per serving: 349.6 kcal calories, 29.6 % calories from fat,