Preheat the oven to 350 degrees Fahrenheit. Line a nine-inch square baking pan with foil, allowing two inches of overhang on two sides.

In a medium bowl, use a fork to mix graham cracker crumbs with margarine, sugar, and a pinch of salt until moistened. Press into the bottom of the prepared pan.

In a medium saucepan, melt cream of coconut and chocolate chips over low heat, stirring until smooth, about three minutes. Add a pinch of salt and stir to blend.

Pour over the crumb crust and spread evenly. Scatter broken pretzels and toasted coconut evenly on top, gently pressing them into the chocolate. Sprinkle with flaky sea salt and bake for 15 minutes, until edges are set.

Let cool, then refrigerate until chilled, about 45 minutes. Unmold and cut into bars while cold.