1 pound cake, vanilla, chocolate, or swirl
1 rectangular box vanilla, chocolate, or swirl ice cream, slightly softened
1/4 cup spiced rum or any liqueur you have on hand
1 jar chocolate sauce
1 cup cocoa powder
Line a meat loaf pan with plastic wrap so that it is completely covered, with lots of extra hanging over the edges.
Cut the pound cake lengthwise in 4 equally thin rectangular slabs. Cut 1 of the rectangles in 1/2 widthwise, then cut another 1 of the rectangles in 1/2 lengthwise. You should have 2 full slabs, 2 thin rectangular strips, and 2 squares.
Begin layering the meatloaf pan with 1 of the full slabs on the bottom, then the 2 strips on either side. Place the 2 squares of pound cake vertically on each end of the pan. The loaf pan should now be completely encased in pound cake.
Lightly brush the pound cake with the liqueur. Scoop the ice cream into the cavity of the pound cake and smooth it out with a small offset spatula or your fingertips so that it is all even around the pan. Once the pan is full of ice cream, top it with the remaining piece of pound cake and press down. Cover the cake with the plastic wrap and put back in the freezer for at least an hour.
Using the overhanging plastic wrap, remove the ice cream cake from the loaf pan. Place the loaf on a serving platter and drizzle with the chocolate sauce. Sprinkle with the cocoa powder and serve.