A peach souffle with warm raspberry sauce is impossible to resist.
Heat oven to 350 degrees; adjust rack to lower third of oven. Lightly spray a 1 1/2-quart souffle dish with vegetable spray, then coat dish with 2 tablespoons of sugar; lightly tap out excess sugar and set aside. In a nonreactive saucepan, combine the peaches, 5 tablespoons sugar, lemon juice, and 4 tablespoons water. Bring to a boil over high heat. Reduce heat to medium and cook until the peaches are broken down and reach a sauce like consistency, about 20 minutes. Puree in a food processor and return to the saucepan.
In a small bowl, stir together Cuarenta y Tres and cornstarch until dissolved. Place the peach puree over medium heat; whisk in the cornstarch mixture until mixture comes to a boil, 3 to 4 minutes; continue whisking for about 30 seconds. Transfer mixture to a large bowl set over ice water to cool; stir frequently for 5 to 10 minutes.
Meanwhile, combine egg whites, cream of tartar, and salt in an electric mixer; beat on medium-low speed until foamy. Slowly add 3 tablespoons sugar, then beat on high speed until stiff but not dry.
Gently fold about a quarter of the beaten egg whites into the chilled peach puree until thoroughly combined. Fold in the remaining egg whites and 3/4 cup raspberries; gently spoon the mixture into the prepared souffle dish. Bake until souffle is firm and has risen 1 to 2 inches over the top rim of dish and is a deep golden brown, about 45 to 50 minutes.
While souffle is baking, make the sauce: In a small saucepan, combine remaining raspberries and remaining 3 tablespoons sugar; place over medium-high heat. Simmer until the berries release their juices and are somewhat broken down, 5 to 7 minutes. Pass through a fine strainer two times, discarding the seeds, and let cool for 5 minutes. Remove souffle from the oven and serve with warm raspberry sauce.
This should be made in a souffle dish that is 8 inches in diameter with 4-inch sides.