Decide whether you will use one large ramekin (family-style) or small or mini ramekins.
Prepare the ramekins. Rub the inside of the ramekins with butter and lightly dust with sugar (use lemon thyme infused sugar to deepen the lemon flavor in the dish - sift the sugar to remove any leaves that still remain).
Preheat the oven to 350 degrees Fahrenheit.
Find a large baking dish or roasting pan, and place the prepared ramekins in the baking dish/pan.
Using a hand-mixer or a stand mixer, cream together the butter and sugar. Add the lemon zest (of two lemons) and combine until light and fluffy.
Add the 3 egg yolks to the butter, zest and sugar mixture until combined.
Add the flour, baking powder and salt. Mix until combined.
Reduce the speed of the mixer, adding the milk and lemon juice (of one lemon only) into the already mixed combination of egg yolks, flour, sugar, butter, etc.. Mix until smooth. Set aside for a moment while you whip the egg whites.
Prior to whipping your egg whites, boil hot water on the stove or in your electric tea kettle. You will need 1-2 cups of boiling water to create a water bath (bain marie) in which you will bake the soufflé/pudding.
In a medium bowl, add the three egg whites. Using a hand whisk or hand mixer with a whisk attachment, whip at a high speed for 2-3 minutes. Then add 1 Tablespoon of sugar (not listed above). Beat/whip until soft peaks form.
Using a spatula, gently fold in egg whites into the lemon batter. Add a little bit at a time, until all is combined but the mixture is still airy.
Pour the batter into your large or 4-6 small ramekins. The ramekins should already be in the baking dish/roasting pan. Once the batter has been poured into the ramekins, pour the boiling water into the baking dish (not into the ramekins :)), to create the water bath which will keep the interior of the soufflé soft.
Place in the 350 degree Fahrenheit stove/oven and bake for 45-50 minutes (for one large ramekin); bake for 20-30 minutes - depending upon the size of your small ramekins. Do your best not to check, but remember, this isn't a true soufflé. It will grow slightly, but not like a classic cheese or chocolate soufflé and therefore, it will also hold its structure a bit better for a just a bit longer. Don't remove until the top is nicely browned.
While the soufflé/pudding is baking, make the topping: In a small/medium mixing bowl, add all three ingredients - crême fraiche, heavy whipping cream and confectioner's sugar - using a hand-mixer with a whisk as an attachment (or use a whisk manually), whip until soft peaks form. Place in the fridge until you are ready to use and the soufflé is just being pulled out of the oven.
Serve and enjoy the soufflé/pudding immediately.
The top will be beautifully brown and underneath will be somewhat runny. If you want it a bit firmer, bake for about 5-7 minutes longer. It will firm up as it cools. I also enjoy this dessert the next day after placing it in the fridge. It is refreshing, cool and full of the citrus flavor that is not overpowering but definitely present. Enjoy!