Maple-Gingerbread Layer Cake with Salted Maple-Caramel Sauce

INGREDIENTS

• 3/4 cup pecan halves,
• 1/4 cup pure maple syrup (preferably Grade B)
• Coarse kosher salt
• 2 1/2 cups all purpose flour
• 1 1/2 teaspoons Chinese five-spice powder
• 1 teaspoon baking soda
• 1/2 teaspoon coarse kosher salt
• 1/3 cup chopped crystallized ginger (1 1/2 to 2 ounces)
• 1 cup maple sugar
• 3/4 cup (1 1/2 sticks) unsalted butter, room temperature
• 2 large eggs
• 3/4 cup hot water
• 2/3 cup mild-flavored (light) molasses
• 1 1/3 cups chilled crème fraîche
• 1 1/3 cups chilled heavy whipping cream
• 1/2 cup maple sugar
• 6 tablespoons powdered sugar
• Ingredient info: Chinese five-spice powder—a spice blend that usually contains ground fennel seeds, Sichuan peppercorns, cinnamon, star anise, and cloves—is available in the spice section of most supermarkets. Crème fraîche is sold at most supermarkets an