Step 1: Prepare the Crust: In a medium bowl, combine graham cracker crumbs, melted butter, and 2 tablespoons of sugar (if using). Press mixture firmly and evenly into the bottom of a 9-inch springform pan. Place in the freezer for 15-20 minutes while you prepare the filling.
Step 2: Bloom the Gelatin: In a small, microwave-safe bowl, sprinkle the unflavored gelatin powder evenly over the 1/2 cup cold water. Let it sit undisturbed for 5-7 minutes to allow the gelatin to bloom and hydrate.
Step 3: Prepare the Skyr Filling: In a large mixing bowl, combine the skyr, 1/2 cup granulated sugar (or preferred sweetener), vanilla extract, and lemon zest (if using). Whisk until the mixture is smooth and well combined. Taste and adjust sweetness as desired.
Step 4: Dissolve the Gelatin: Microwave the bloomed gelatin for 15-20 seconds, or until it is completely dissolved and clear. Do not boil. Let it cool slightly for 1-2 minutes.
Step 5: Combine Gelatin with Skyr Mixture: While continuously whisking the skyr mixture, slowly pour the slightly cooled, dissolved gelatin in a thin, steady stream. Whisk thoroughly to ensure the gelatin is fully incorporated and no lumps form.
Step 6: Assemble and Chill: Pour the skyr filling evenly over the chilled graham cracker crust in the springform pan. Gently tap the pan on the counter a few times to release any air bubbles. Cover the pan loosely with plastic wrap and refrigerate for at least 4-6 hours, or preferably overnight, until the cheesecake is completely set and firm.
Step 7: Garnish and Serve: Once the Viral Skyr Cheesecake is fully set, carefully run a thin knife around the edge of the pan before releasing the springform. Transfer to a serving platter. Garnish with your desired toppings such as fresh berries, fruit compote, or a drizzle of chocolate. Slice and serve immediately. Store any leftovers in an airtight container in the refrigerator.