Chocolate Chip Skillet Cookie

Preheat oven to 350° and grease a 10" cast-iron skillet with cooking spray. In a large bowl, cream butter and sugars with a hand mixer until light and fluffy. Beat in egg and vanilla. Add flour, baking soda, and salt. Mix until just combined. Fold in 1 cup chocolate chips. Spread dough into skillet in an even layer. Top with remaining 1/4 cup chocolate chips and sprinkle with flaky sea salt. Bake until edges are golden, 20 to 24 minutes. Serve warm with ice cream, warm caramel sauce, and chocolate syrup, if desired.