Grapefruit-Orange Crostatas

Ingredients

• 3/4 cup (1 1/2 sticks) unsalted butter, cut into pieces, frozen 10 minutes
• 1 3/4 cups all-purpose flour
• 2 tsp. sugar
• 1 tsp. kosher salt
• 1/4 tsp. distilled white vinegar
• 1/2 cup semolina flour
• 1 tsp. kosher salt
• 7 Tbsp. sugar, divided
• 4 1/2 tsp. all-purpose flour, plus more for dusting
• 1 grapefruit
• 1 orange
• 3/4 tsp. vanilla paste or extract
• 4 Tbsp. unsalted butter, room temperature, plus 2 Tbsp. melted
• 1 large egg
• 1 large egg yolk