Pre-heat oven to 375 degrees F and position oven rack to the lower ⅔.

Make the lemon cream: In a medium pot, whisk together the egg yolks, milk, lemon juice and zest, cornstarch, sugar and salt. Over medium heat, whisk until the mixture begins to bubble, about 3-4 minutes. It will continue to get thicker, but constantly whisk it. Continue until it is very thick.

Turn heat off and whisk in the butter and vanilla extract. Transfer the hot cream mixture to a large bowl filled with ice to help cool down the mixture. Whisk every few minutes until it gets to room temperate.

Make the meringue (egg whites): In a stand mixer fitted with a whisk attachment, add egg whites. Start on low and work to medium speed. You will see the egg whites begin to "break up" and start to get foamy. Add cream of tartar and continue whisking.

Continue whisking and gradually get a little faster. When whites are starting to form and are at "soft peaks" add confectioners sugar slowly, about 1Tb at a time while the whisk is going. Continue whisking until "stiff peeks" form.

Next, place the egg whites and pastry cream bowl next to each other. Using a large, soft spatula take a large dollop of cream mixture and add it to the egg whites. Do not mix heavily, you want to FOLD it in. Fold by taking your spatula to the side0under-up. You will see streaks of yellow and continue folding gently. Add the rest of the cream mixture about ½c at a time until Incorporated.

For the molds: Grease a 6cup mold with softened butter all over and dust with powdered sugar.

*This recipe is enough for a 6cup mold plus 2 small individual molds.

Make the collar: Tear a long enough piece of tin foil that is long enough to wrap around the mold. Fold in half so it is not "too tall". Grease the inside of the foil with butter and wrap around mole, securing at handles.

Pour the souffle mixture into the dish and level off the top. Wrap the foil around the mold. (Easier after your pour mixture in).

Bake at 375 for exactly 20 minutes. No peeking! When done, dust with powdered sugar.