Baked French Toast with Pecan Crumble - French Recipe

Ingredients

• 1 1-pound loaf challah
• sliced 1" thick
• Unsalted butter
• room temperature (for baking dish)
• 4 large eggs
• 4 large egg yolks
• 2 cups heavy cream
• 2 cups whole milk
• 1/2 cup sugar
• 1 teaspoon vanilla extract
• 1/2 teaspoons ground cinnamon
• 1/2 teaspoons ground nutmeg
• 1/2 teaspoons kosher salt
• 1/2 cup pecans
• 2 tablespoons chilled unsalted butter
• cut into pieces
• 2 tablespoons light brown sugar
• Blackberry Syrup