Mini Cheesecakes with Salted Caramel

Ingredients

• 1 1/4 cups fine graham cracker crumbs
• 5 tablespoons unsalted butter (melted)
• 1 tablespoon granulated sugar
• 16 ounces full-fat cream cheese (softened)
• 1/4 cup sour cream (not low-fat)
• 1/2 cup granulated sugar
• 2 eggs (separated)
• A pinch of salt
• 1/4 teaspoon vanilla
• 3 tablespoons heavy cream (warmed)
• 2 tablespoons unsalted butter (preferably European style, like Plugra)
• 1/2 teaspoon fleur de sel or fine sea salt (plus extra for topping)
• Whipped cream (optional)