Step 1: Prepare the Crust

1. In a medium bowl, combine the graham cracker crumbs, melted butter, granulated sugar, and salt until the mixture resembles wet sand.
2. Press the mixture firmly into the bottom and slightly up the sides of a 9-inch springform pan using the bottom of a measuring cup.
3. Place the crust in the refrigerator to chill while preparing the filling.

Step 2: Prepare the Orange Gelatin Mixture

1. In a small bowl, dissolve the orange-flavored gelatin in 1/4 cup boiling water, stirring until completely dissolved.
2. Set aside to cool slightly but not set (about 5-10 minutes).

Step 3: Make the Cheesecake Filling

1. In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and fluffy (about 2 minutes).
2. Add the granulated sugar and continue beating until well combined and smooth.
3. Mix in the orange juice, orange zest, and vanilla extract until fully incorporated.
4. With the mixer on low speed, gradually pour in the cooled gelatin mixture until completely blended.
5. If using food coloring, add a few drops now for a more vibrant orange color.

Step 4: Incorporate the Whipped Cream

1. In a separate bowl, whip the heavy cream until stiff peaks form.
2. Gently fold the whipped cream into the cream cheese mixture using a rubber spatula, being careful not to deflate the whipped cream.
3. Continue folding until no white streaks remain and the mixture is uniform in color.

Step 5: Assemble and Chill

1. Pour the cheesecake filling over the prepared crust and smooth the top with an offset spatula.
2. Tap the pan gently on the counter a few times to release any air bubbles.
3. Cover the cheesecake with plastic wrap and refrigerate for at least 4 hours, preferably overnight, until firmly set.

Step 6: Prepare the Topping

1. Just before serving, whip the heavy cream with powdered sugar and vanilla extract until stiff peaks form.
2. Remove the cheesecake from the springform pan and transfer to a serving plate.
3. Pipe or spread the whipped cream on top of the cheesecake.
4. Garnish with fresh orange slices and additional orange zest.