Lush Vanilla Berry Pudding

Name: Lush Vanilla Berry Pudding
Ingredients: 2 large egg yolks; ½ cup (100 g) sugar; ⅓ cup (37 g) cornstarch; 2¼ cups whole milk, divided; 2 tsp. Diamond Crystal or 1 tsp. Morton kosher salt, divided; ½ cup (1 stick) unsalted butter, cut into 1 pieces, room temperature; 1 Tbsp. vanilla bean paste or extract; 2 cups chilled heavy cream; ⅓ cup strawberry or other berry jam; 18 oz. mixed fresh berries (such as raspberries, blackberries, and/or blueberries), halved if large; ½ 11-oz. box Nilla Wafers