Draw an oval and two vertical lines.
Draw a horizontal line to divide the oval in 1/2.
Draw a dot to indicate the center of the oval. Draw two vertical lines on either side.
Add the bottom of the cake.
After erasing it should look like this.
Draw two diagonal lines from the top edge of the cake back to the dot.
Draw a vertical line from the dot. It should stop about 1/2-3/4 of the way down.
Draw diagonal lines from the bottom of the cake back to the bottom of the horizontal line.
Add icing between the layers. You could make your cake a 3 layer cake with two layers of icing if you wish.
Paint or color.