Preheat oven to 350°F. Butter a 10x15x¾-inch baking pan (or line pan with parchment.)
Cream butter and sugar. Beat in eggs and ¼ cup sweetened condensed milk. Combine flour, cocoa, and salt. Add dry ingredients into creamed mixture; mix until well blended. Spread mixture in the prepared pan.
Bake 18-20 minutes.
Combine 1 cup sweetened condensed milk with egg in a small saucepan. Add butter and heat over mid heat until thickened. Remove from heat and stir in coconut and pecans. Cool slightly and spread over brownie base. Cool completely and cut into squares.
14 oz. can of sweetened condensed milk equals 1¼ cups.