First, crush the graham crackers in a food processor. Measure 1 cup of crumbs, and remove any extra from the food processor. In a seperate bowl, whisk together the egg yolks and cream.
Add the flour to the food processer and pulse until the flour and graham cracker crumbs are combined. Then quickly cut the cold butter into large chunks and add to the food processor. Pulse until the butter is in small pieces, about 8-10 pulses.
Add the yolk and cream mixture to the food processor and pulse until the dough forms a large mass, about 8-10 more pulses. Then flatten the dough into a small rectangle and cover with plastic wrap. Chill it in the refrigerator for about 30 minutes.
Measure your tart pans. Add the diameter of the pan and the height of both sides to get the diameter of the circles you will need to cut out. For my 4 inch tart pans, I cut out 6 inch circles.
Roll the crust dough until it is about 1/4 an inch thick. Use a cookie cutter or template to cut out the circles. If you run out of room, combine the scraps and roll them out again.
Press the crusts into the tart pans. If the crusts are hanging over, press the rolling pin over the pan edges to cut off the excess. Use a fork to poke holes in the bottoms of the crusts, then chill them for about 20 minutes. Preheat your oven to 400° F (220° C.)
After the crusts have chilled, bake them for about 5 minutes at 425° F. Then lower the temperature to 350° F (180° C) and bake for another 5 minutes. If you are using pie weights, keep them in for about the first 7 minutes of baking, and then remove.
Allow the crusts to cool for about 20 minutes before removing them from the pans.