Peanut Butter Fudge Puddles (Cookie Cups)

Bahan-bahan (36 porsi)

• 1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature
• 1/2 cup (100g) packed light or dark brown sugar
• 1/2 cup (100g) granulated sugar
• 1 large egg, at room temperature
• 2/3 cup (156g) creamy peanut butter
• 1 teaspoon pure vanilla extract
• 1 and 1/4 cups (156g) all-purpose flour (spooned & leveled)
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 8 ounces (226g) semi-sweet chocolate, chopped (see Note)
• 1 teaspoon vegetable oil or coconut oil
• 8 ounces (226g) mascarpone cheese, at room temperature
• optional: 1/2 cup (120g) Heath toffee bits or chopped peanuts, for topping