Raspberry Peach Frozen Cake

Nonstick vegetable oil spray
1 13-ounce package almond shortbread cookies
1/2 cup sliced almonds, toasted
1 1/2 teaspoons grated lemon peel
3 large peaches (about 20 ounces), peeled, pitted, diced

2 tablespoons peach preserves
3 1/2-pint containers raspberries

2 tablespoons raspberry preserves
2 1/2 cups chilled heavy whipping cream
9 large egg yolks
3/4 cup sugar
1/3 cup light corn syrup
2 tablespoons (1/4 stick) unsalted butter, room temperature
2 tablespoons peach schnapps

Spray 9-inch springform pan with 3-inch-high sides with nonstick spray. Finely grind shortbread cookies, almonds, and lemon peel in processor. Press half of mixture over bottom of prepared pan. 

Puree peaches in processor. Transfer puree and peach preserves to heavy deep-sided saucepan and bring to simmer over medium heat. Cook until reduced to 1 cup, stirring often, about 10 minutes (color of puree will darken slightly). Transfer to bowl and chill in freezer until cool, about 15 minutes. 

Puree raspberries in processor. Strain through sieve set over medium bowl, pressing to extract as much fruit as possible. Heat raspberry preserves and add to puree. Chill. 

Whisk 1/4 cup cream, egg yolks, sugar, corn syrup, and butter in large metal bowl to combine. Set bowl over saucepan of simmering water (do not allow bottom of bowl to touch water). Whisk constantly until parfait base thickens and thermometer inserted into base registers 160°F, about 8 minutes.

Remove bowl from over water. Using electric mixer, beat parfait base until billowy and completely cool, about 8 minutes. Divide between 2 medium bowls (about 1 cup parfait base in each bowl). Beat remaining 2 1/4 cups cream in large bowl until medium peaks form. Fold cool peach puree and schnapps into 1 parfait base, then fold in half of whipped cream. Spread peach parfait in prepared pan. Sprinkle remaining macaroon mixture over. Place in freezer. 

Fold 1 cup of raspberry puree (reserve remaining puree for another use) into parfait base in second bowl. Fold in remaining whipped cream. Spread parfait over macaroon mixture in pan. Cover; freeze at least 8 hours and up to 2 days. 

To serve: use  heated knife, cut around parfait cake to loosen; remove pan sides and slice.