3 cups (18 oz.) semi-sweet chocolate chips
1 (14 oz.) can sweetened condensed milk
1/4 tsp salt
1 1/2 teaspoons vanilla extract
3/4 cup creamy peanut butter
1/4-1/2 teaspoon sea salt
Line 8- or 9-inch square pan with foil, extending foil over edges of pan.
Melt chocolate chips with sweetened condensed milk and salt in heavy saucepan over low heat.
Remove from and stir in vanilla. Spread evenly into prepared pan. Top with creamy peanut butter and using a spreader make an even layer over fudge.
Using a sharp knife, swirl fudge and peanut butter together and sprinkle 1/4-1/2 teaspoon of sea salt on top of the fudge.
Chill 2 hours or until firm. Remove from pan by lifting edges of foil. Cut into squares.