Spinach Frittata With Raisins and Pine Nuts

Name: Spinach Frittata With Raisins and Pine Nuts
Ingredients: 1 tsp. extra-virgin olive oil; 3 Tbsp. pine nuts; 3 Tbsp. golden raisins; 1 tsp. chopped fresh oregano; 1 packed tsp. grated lemon zest (from about 1 medium lemon); Kosher salt; 2 Tbsp. extra-virgin olive oil; 1 medium yellow onion, finely chopped; 5 ounces baby spinach (about 4½ cups); 1 medium garlic clove, minced, grated, or pushed through a press; 8 large eggs; ⅓ cup (50 g) freshly grated Parmesan; 1½ tsp. chopped fresh oregano; ½ tsp. kosher salt; ¼ tsp. freshly ground black pepper; ⅓ cup (80 g) mascarpone; Finely chopped fresh flat-leaf parsley, for sprinkling