Brioche Ice Cream Sandwich With Raspberries

Name: Brioche Ice Cream Sandwich With Raspberries
Ingredients: For the vanilla-raspberry ripple ice cream:; 5 large egg yolks; 1 1/2 cups granulated sugar, divided; 1/2 teaspoon kosher salt, divided; 2 cups heavy cream; 1 cup whole milk; 1 vanilla bean, halved with seeds scraped out; 1 (12-ounce) bag frozen raspberries (or 3 pints fresh); 1 tablespoon freshly squeezed lemon juice (about half a lemon); For the ice cream sandwiches:; 4 St Pierre Brioche Burger Buns; 4 scoops vanilla-raspberry ripple ice cream; 1/4 cup reserved raspberry preserves (optional); 1/4 cup freeze-dried raspberries, crushed into a coarse powder (freeze-dried strawberries would also work)