Grammie's Raspberry Meringue Cookie Bars

Ingredients

• 3 cups all-purpose flour
• 1.5 cups butter , softened
• 1.5 cups powdered sugar
• 6 eggs , separated
• 1.5 cups white sugar
• 2 teaspoons rice vinegar
• 2 teaspoons cornstarch
• 0.75 cups raspberry preserves , or to taste

Instructions

1. 1

   Preheat the oven to 350 degrees F (175 degrees C).

2. 2

   Beat flour, butter, powdered sugar, and egg yolks together in a large bowl. Press into the bottom of a 9x13-inch baking pan.

3. 3

   Bake in the preheated oven until lightly golden, about 12 minutes.

4. 4

   Meanwhile, beat egg whites with an electric mixer until foamy. Gradually add white sugar, continuing to beat until stiff, shiny peaks form. Fold in rice vinegar and cornstarch with a spatula.

5. 5

   Remove crust from the oven; cover with jam. Spoon meringue over the top. Continue baking until meringue is golden brown, about 25 minutes. Let cool completely before cutting into bars.