Mix first 3 ingredients in medium bowl. Set spiced sugar aside. Mix flour, 3/4 cup sugar, baking powder, and salt in large bowl. Using fingertips, rub in chilled butter until coarse meal forms. Add cream and vanilla; stir until moist clumps form. Gently knead dough on lightly floured surface just until smooth.
Roll out dough on lightly floured surface to 9×15-inch rectangle. Brush with melted butter. Sprinkle with spiced sugar. Starting at 1 long side, roll up dough jelly-roll style. Transfer to baking sheet. Cover log with plastic wrap and refrigerate at least 1 hour and up to 1 day.
Preheat oven to 350°F. Blend sugar, vanilla bean, and flour in processor until vanilla is finely chopped; place in large bowl. Add peaches and lemon juice; toss to coat. Transfer peach mixture to 10-inch-diameter cake pan with 2-inch-high sides. Bake until filling is bubbling, about 30 minutes.
Cut dough log crosswise into 1-inch-thick biscuits. Place biscuits atop filling. Bake until biscuits are golden, about 45 minutes. Cool at least 10 minutes. Dust with powdered sugar and serve warm.
1/2 cup (packed) golden brown sugar
2 tablespoons minced crystallized ginger
1/2 teaspoon ground cinnamon
2 cups all purpose flour
3/4 cup sugar
2 teaspoons baking powder
1/2 teaspoon salt
1/2 cup (1 stick) chilled unsalted butter, cut into small pieces
2/3 cup whipping cream
2 teaspoons vanilla extract
1 tablespoon butter, melted
1/2 cup sugar
1 vanilla bean, coarsely chopped
1 tablespoon all-purpose flour
4 pounds peaches, peeled, cut into 1/2-inch-thick slices
2 teaspoons fresh lemon juice