2 1/2 cups finely crushed pretzel crumbs
12 tablespoons unsalted butter
(1 1/2 sticks), melted
3 tablespoons brown sugar
2 envelopes unflavored gelatin
3 cups white grape juice
1 cup granulated sugar plus 3 additional tablespoons
1 cup heavy cream
8 ounces cream cheese, cut into 1-inch pieces and softened at room temperature for 30 to 45 minutes
3 cups fresh strawberries , hulled and thinly sliced, and chilled
1. Adjust oven rack to middle position and heat to 350 degrees. Coat bottom of 13 by 9-inch baking dish with cooking spray.
2. Toss pretzel crumbs, butter, and brown sugar together in medium bowl until evenly combined. Press firmly into even layer on bottom of baking dish. Bake until fragrant and slightly deepened in color, about 10 minutes. Cool completely.
3. Meanwhile, sprinkle gelatin over 1 cup grape juice in small bowl. Let stand 5 minutes to soften.
4. Bring another 1 cup grape juice and 1 cup granulated sugar to boil in medium saucepan over medium-high heat. Remove pan from heat, add gelatin mixture, and whisk to dissolve any lumps, about 1 minute. Stir in remaining 1 cup grape juice. Transfer mixture to medium bowl and refrigerate until mixture just begins to set, about 1 hour.
5. Meanwhile, beat heavy cream and remaining 3 tablespoons granulated sugar in medium bowl with electric mixer at medium-high speed until cream just holds soft peaks, about 2 minutes. With mixer running, gradually add cream cheese, then whip until mixture is well blended, scraping down sides of bowl as necessary, about 3 minutes. Spread mixture evenly over cooled pretzel crust and top with strawberries. Let chill in refrigerator until gelatin is ready to use. Carefully spoon gelatin over strawberries, cover with plastic wrap, and refrigerate until completely set, at least 4 hours or overnight. Cut into 20 squares and serve. (Bars can be refrigerated for up to 2 days.)