Unfold piecrusts; stack piecrusts on a lightly floured surface. Roll into one 12-inch circle. Fit piecrust into a 9-inch pieplate according to package directions; fold edges under, and crimp.
Bake piecrust at 450° for 8 minutes; cool on a wire rack.
Whisk together sugar and next 9 ingredients until blended. Pour into piecrust.
Bake at 350° for 40 to 45 minutes or until center is set, shielding edges of crust with aluminum foil after 20 minutes to prevent excessive browning. Cool on a wire rack. Garnish, if desired.
Lemon-Lime Chess Pie: Substitute fresh lime juice for tangerine juice and 1 teaspoon fresh lime rind and 1 teaspoon fresh lemon rind for tangerine rind. Garnish with sweetened whipped cream; lime and lemon wedges; and grated lime and lemon rind, if desired.
Orange Chess Pie: Substitute fresh orange juice and rind for tangerine juice and rind. Garnish with sweetened whipped cream, orange slices, and orange rind, if desired.
Grapefruit Chess Pie: Substitute fresh grapefruit juice and rind for tangerine juice and rind. Garnish with sweetened whipped cream and grapefruit rind or lime rind and lime pieces, if desired.