Bake in preheated oven to 365° for 20-25 minutes. Once baked, let the triangles cool completely before adding filling.
Combine the dulce de leche, butter and rum in a bowl and mix on the lowest speed just until creamy. (Don’t over beat or it will become “runny”.) Refrigerate until ready to use.
With a sharp knife cut each triangle in half. Spread some cream on both side and close back up. Add just a little bit of the cream to the top of the triangle. Do this to all the triangles.
Melt the chocolate. Set aside for chocolate to completely cool.
Place your chocolate in a plastic bag, snip off a tiny edge and drizzle the chocolate over the triangle.