Melt the 3 Tablespoons of margarine in a large microwave-safe mixing bowl. Add chocolate to hot margarine and stir well. Microwave for another 30 seconds and stir until chocolate is melted and smooth. Let mixture cool for about 5 minutes.
Beat the sugar into the melted chocolate mixture. With a mixer on medium, add the egg replacer and vanilla, increase mixer speed to high and beat for about a minute.
Mix the flour, cocoa powder, baking powder and salt together in a separate bowl. By hand, stir it into the batter until incorporated. Stir in about 1/2 cup of the chocolate chips.
Preheat oven to 350 degrees F. Line sheets with parchment paper or a silpat. Scoop up big two-tablespoon sized mounds and arrange them on cookie sheets a few inches apart. Mine didn't spread so press down a bit. Bake one sheet at a time for 8-10 minutes. Cookies should still be a little shiny when you take them out, but baked. Mine took 10 minutes.
Let cool on cookie sheets for a few minutes then transfer to cooling racks.
To make icing, melt the last bit of chocolate chips and margarine/shortening together in microwave or in a metal bowl set over hot water. Drizzle the chocolate over the cookies or if it's too thick to drizzle, transfer it to a freezer bag, snip off the corner and squeeze it over the cookies.