Make the lemon curd cream first so that it has time to chill. Set a fine mesh strainer over the container of a blender.
Combine the sugar and the lemon zest in a medium saucepan. Rub the sugar and zest together between your fingers until the sugar is moist, clumpy, and very aromatic.
Whisk in the eggs. Whisk in the lemon juice.
Place the saucepan over medium-low heat. Cook, whisking contantly until the mixture reaches 180F on an instant read thermometer. The curd will start to thicken and leave tracks before it reaches 180F.
Remove the curd from the stove and immediately strain the mixture in the strainer over the blender container. Discard the zest and any curdled egg.
Let the curd rest at room temperature in the blender container, stirring occasionally, until it cools to 140F. This can take about 10 minutes.
Place the lid on the blender and turn on high. Remove the lid and add the butter, a couple tablespoons at a time.
Once all the butter has been added, place the lid back on, and keep blending for 2-3 minutes to get perfectly creamy, light and airy lemon curd cream.
Pour the cream into a storage container and press a piece of plastic wrap against the surface to prevent a skin from forming. Chill the cream for at least 3 hours or overnight.