Preheat oven to 350 degrees. In a large or medium mixing bowl, beat butter until creamy. Add the sugar and flour. Mix until blended and the dough is crumbly.
With floured hands, press the dough into a 9x13 pan. Bake crust for 15 minutes, or until the edges are just starting to become golden. (Don't overbake.)
When the crust has a few minutes left to bake, heat the condensed milk in a small sauce pan on medium. Add the chocolate chips and cocoa and stir until melted.
Spread the chocolate filling evenly over the hot crust. Use a teaspoon to dot the jam or fruit spread over the chocolate. Top with the strawberries and sprinkle with sugar.
Bake for another 27-30 minutes. Sprinkle lightly with sea salt. Let cool completely before cutting into bars. The bars taste best when cooled and the jam is set.