Place the mango and sugar in a blender and puree until it is smooth.
Pour the mango puree into a saucepan and cook over medium-high heat until the mixture is hot but not boiling.
Whisk the egg yolks together in a large non-reactive bowl and in a separate small bowl mix add the lime juice and sprinkle the gelatin over it to let it dissolve.
When the mango puree is ready add it to the egg yolks very slowly, whisking constantly. Then pour the mixture back into the saucepan and cook over medium-high heat, stirring constantly until the mixture thickens, 5-7 minutes. Note: You can tell when it is thick enough by dragging your spoon through it. If it leaves a trail in the mango curd then it is ready.
When the curd is thick enough remove it from the heat and stir in the gelatin mixture and the cold butter stirring until everything is dissolved.
Pour the curd through a fine mesh strainer into a glass bowl. This will remove any bits of egg that may have cooked in the heat. Then cover the curd placing plastic wrap directly against the surface of the curd and put it in the refrigerator until it has cooled completely and firmed up enough to spread, at least 3 hours.
Note: This makes a lot of mango curd. If you have more than you can use you can freeze it for later or just fold it into some whipped cream and eat it throughout the week….don’t judge me!