Preheat the oven to 375 degrees F. Grease and flour a 13 by 9 by 2-inch pan.
In a bowl, beat the eggs and butter together. Add the brown sugar, and then gradually add the flour and mix well. Stir in the vanilla. Fold in the nuts, chocolate chips, and coconut, if using. Spread the batter in the prepared pan and bake for 25 to 30 minutes. Cool.
Prepare the pudding according to the package directions. Let cool slightly.
Beat the cream with the powdered sugar until stiff.
Crumble the brownie into chunks and then layer one-third into a large glass bowl. Spoon half the pudding over the brownies. Spoon half the whipped cream over the pudding and scatter one-third crumbled brownie. Sprinkle with some chopped peanuts, spoon the remaining half pudding and whipped cream, and sprinkle with some more peanuts. Layer the remaining one-third brownie, drizzle with chocolate sauce, and garnish with mint leaves. Refrigerate until serving time.