Strawberry Pistachio Semifreddo

Stir together ¾ cup sugar and 1½ tablespoons water in a small saucepan, until a wet sand consistency is reached. Heat over medium-high heat, and stir until sugar is dissolved. (Do not stir after it starts to boil.) Boil until sugar turns a light caramel color throughout. Remove from heat; stir in pistachios. Pour mixture onto a nonstick baking mat, and let cool completely, about 30 minutes. Break up caramelized pistachios and roughly chop, or pulse in a food processor. Set aside.

Line a 10x5-inch loaf pan with plastic wrap, letting excess extend over sides of pan. Place pan in freezer.

Stir together remaining 1¼ cups sugar and remaining ¼ cup water in a small saucepan. Heat over medium-high heat, and stir until sugar is dissolved. (Do not stir after it starts to boil.) Boil until a candy thermometer registers 238°F.

Beat egg whites and salt at medium-high speed in the bowl of a stand mixer fitted with the whisk attachment until soft peaks form. With mixer running, add hot sugar syrup in a slow, steady stream, beating until meringue is stiff and cool, about 5 minutes. Transfer to a large bowl; set aside.

Clean bowl of stand mixer and whisk attachment. Using the whisk attachment, beat cream and vanilla at medium-high speed until stiff peaks form. Fold whipped cream into meringue in 2 batches. Reserve ½ cup caramelized pistachios for garnish. Fold remaining caramelized pistachios into meringue.

Scoop one-third of meringue mixture into bottom of prepared pan. Top with ⅓ cup Strawberry Sauce, and swirl gently with a spoon. Repeat layers twice. Cover with a piece of plastic wrap, and freeze for 24 hours.

Turn out loaf onto a chilled serving platter when ready to serve. Top with remaining ¾ cup Strawberry Sauce and reserved ½ cup caramelized pistachios. Top with strawberries, if desired. Serve immediately.

For the Strawberry Sauce

Bring all ingredients to a boil over medium heat in a medium saucepan. Reduce heat to low, and simmer for 10 minutes. Remove from heat; place in a small bowl. Refrigerate until well chilled.