Step 1

Place the raspberries, 1/4 cup of sugar, 1/4 teaspoon of salt, and 2 tablespoons of water in a 3-quart non-reactive saucepan. Cook the raspberries over medium heat until they start to break down. Use a potato masker to completely break down the berries Strain the berries through a fine-mesh strainer to remove the seeds. You should have 1 cup of puree. Allow the raspberries to cool to room temperature. Add the lemon juice and remaining 1/4 cup of sugar and taste the mixture. If it is still a little tart add additional sugar 1 tablespoon at a time until desired sweetness is reached.

Step 2

Place the raspberry puree back in the 3-quart saucepan. Rinse and dry the bowl and place it next to the stove with a medium-coarse strainer Add the whole eggs and egg yolks to the raspberry-lemon mixture and whisk to combine.

Step 3

Cook the curd over medium-low heat, stirring constantly with silicone spatula or metal whisk, until the mixture is thickened and registers 180 degrees in multiple spots, 5 to 7 minutes.

Step 4

Off heat, whisk in the butter one tablespoon at a time until incorporated. Strain curd through the medium-coarse strainer into the bowl. Press a piece of plastic wrap directly onto surface of the curd and refrigerate for at least 3 hours to chill and thicken it. (Curd can be refrigerated for up to 7 days.)