Line a muffin tin with plastic wrap. You will only use 6 of the cups.
Slice one pound cake widthwise into twelve 1/4-inch slices. (An easy way to make the slices even is to first cut the cake in half, then cut each half into six pieces). Using a 5-ounce can (a small tomato paste can works great), cut 6 circles out of 6 of the slices of cake. With the remaining 6 slices, use a 15-ounce can to make slightly larger circles of cake for the tops. You should end up with six small circles and six large circles. Reserve.