Preparation for sauce:
In a medium sauce pan, cook diced rhubarb with 1 ½ cups sugar, orange juice and orange zest for about 20 minutes.
Add Grand Marnier and allow to cool.
To test, make sure it’s cohesive and its surface wrinkles when nudged.
Place strawberries in food processor, pulse 5 times and add to the sauce.
Preparation for cheesecake:
Preheat oven to 350°F.
Wrap exterior of a 10-inch spring-form pan (including base) in a double layer of foil; set aside.
In a medium bowl, stir together cracker crumbs, melted butter, and 4 tablespoons sugar.
Press crumb mixture firmly onto bottom of pan. Bake until set, about 10 minutes. Let cool in pan on a wire rack.
Reduce oven temperature to 325°F.
In an electric mixer bowl fitted with a paddle attachment; mix cream cheese on medium speed until fluffy, about 3 minutes. With mixer on low, add remaining 1 ½ cups sugar.
Add salt and vanilla and mix until well combined.
Add eggs one at a time, mixing each until just combined.
Pour cream cheese filling over crust.
Drop strawberry rhubarb sauce by the teaspoon in dots on top. With a wooden skewer or toothpick, swirl sauce into filling.
Set cake pan inside a large, shallow roasting pan to reach halfway up sides of cake pan.
Bake until cake is set but still slightly wobbly in center, approximately 1 hour.
Turn oven off, slightly open the oven door and let cheesecake cool completely in the oven.
Refrigerate, uncovered, at least 6 hours or overnight. Before unmolding, run a knife around edge of cake.