No-Bake S'More Bars

1 stick unsak=lted butter, softened
1 cup packed brown sugar
1 tsp. vanilla
2 cups graham cracker crumbs
1 cup flour
1 tsp. flakey sea salt or 1/2 tsp kosher salt
1 (14oz) can sweetened condensed milk
1/2 cup chocolate chips
1 1/2 cups mini marshmallows

Line a 13x9 baking pan with foil or parchment so it extends up the sides. Spray lightly with nonstick spray.

In a large bowl, beat the butter, sugar and vanilla until light and fluffy, about 2 minutes. Beat in the graham cracker crumbs, flor and salt. Beat in the condensed milk. With a wooden spoon, stir in 1 cup of the chocolate chips and 1 cup of the marshmallows. 

Transfer the mixture to the prepared pan and use a spatula to press into an even layer. Sprinkle the surface with with the remaining 1/2 cups of chocolate chips and marshmallows, pressing gently to adhere. Cover with plastic wrap and chill until firm.

Use the foil to lift the bars out of the panin one piece. Cut into small bite sized squares. Store in an airtight container in the refrigerator for up to 5 days.