Crème Fraîche Chocolate Chunk Cookie Bars

Bahan-bahan (24 porsi)

• 2 sticks (1 cup) salted butter, at room temperature
• 2/3 cup light brown sugar
• 1/2 cup granulated sugar
• 2 large eggs
• 2 teaspoons vanilla extract
• 2 1/4 cups all-purpose flour
• 1 teaspoon baking soda
• 2 -3 cups semi-sweet chocolate chunks or chips
• flaky sea salt, for topping
• 8 ounces crème fraîche ((mascarpone or cream cheese can be used in an equal amount))
• 1 egg
• 1/4 cup granulated sugar