Lime Curd Tart

This curd is lip-puckering tart!

3/4 cup butter, softened
1/2 cup sugar
1/2 tsp. vanilla extract
1 3/4 cups all-purpose flour
Pinch of salt
1/2 cup butter, softened
1 1/2 cups sugar
Zest and juice from 4 limes
4 eggs
Pinch of salt
Fresh blackberries

1. Beat 3/4 cup butter and 1/2 cup sugar with an electric mixer just combined. Beat in vanilla, flour, and pinch of salt. Beat on low speed until the dough starts to come together. Spoon dough into a lightly greased 10-inch tart pan. Press dough into bottom and up sides of pan. Prick dough with a fork.
2. Bake at 350° for 15 minutes. Remove from oven to cool completely.
3. Meanwhile, beat 1/2 cup butter, 1 1/2 cups sugar, and lime zest with mixer until creamy. Stir in the lime juice. Add eggs, 1 at a time, beating until blended after each addition. Add in pinch of salt.
4. Pour lime mixture into a saucepan, and cook over low heat, stirring constantly, about 10 minutes or until thickened. Remove from the heat.
5. Pour lime curd into tart shell. Top curd with blackberries. Cover and chill until ready to serve.