In a large mixing bowl with a stand mixer, or in the bowl of a stand mixer, beat the peanut butter, granulated sugar and brown sugar together on high speed until creamy and smooth, 2-3 minutes. Add the egg, vanilla, baking soda and salt and mix until combined.
1 cup creamy peanut butter, 1/2 cup granulated sugar, 1/2 cup light brown sugar, 1 large egg, 2 teaspoons vanilla extract, 1 teaspoon baking soda, 1/2 teaspoon sea salt