Preheat your oven to 350°F (175°C).
Mix graham cracker crumbs, melted butter, and 3 tablespoons sugar in a bowl until well combined. Press the mixture into the bottom of a 9-inch springform pan to form the crust.
In a mixing bowl, beat the softened cream cheese with 1 cup sugar and vanilla extract until smooth and creamy.
Add eggs one at a time, fully incorporating each before adding the next. Blend in sour cream.
Pour the cream cheese mixture over the crust in the springform pan.
Bake in the preheated oven for 45 to 50 minutes, or until the center is almost set. Turn off the oven, open the oven door slightly, and let the cheesecake cool in the oven for 1 hour.
While the cheesecake is baking, combine redcurrants, 1/2 cup sugar, water, and orange zest in a saucepan over medium heat. Cook until the redcurrants burst and the sauce thickens, about 15 minutes.
Once the cheesecake has cooled, spread the redcurrant topping over the top.
Chill the cheesecake in the refrigerator for at least 6 hours, preferably overnight, before serving.