Instead of slicing up one big cheesecake, just give everyone their own little cheesecake!
Turn the oven up to 325 F. While that's heating up, grease a 6-cup muffin pan.
Mix the cracker crumbs, sugar, and margarine with a fork in a mid-sized mixing bowl until combined. Measure out a rounded tablespoon of that mix into the bottom of each muffin cup, giving them a firm press. Bake the pan in the pre-heated oven for 5 minutes, then take it out to let it cool off. Don't turn off the oven just yet!
In a separate bowl, beat the cream cheese, sugar, lemon juice, lemon zest and vanilla together until it's a single, fluffy mix. Crack the egg and mix it into the bowl.
Pour the cream cheese mix into the muffin cups. You want each cup to be about 3/4 full. Bake the pan for 25 minutes. Let the cakes cool completely in pan, then take them out and let them chill in the fridge until you want to eat them.