Step 1: Brine the Limes (Optional, but Highly Recommended). In a small bowl, combine the 1/4 cup dill pickle brine, and the 1/4 cup water. Add whole key limes (or regular limes) to the brine, making sure they’re submerged. Let them sit at room temperature.

Step 2: Make the Crust – Preheat Oven. Preheat the oven to 325°F (160°C). Wrap heavy-duty foil around the bottom and sides of a 9-inch springform pan. Spray the inside of the pan lightly with nonstick cooking spray.

Step 3: Combine Crust Ingredients. In a medium bowl, stir together the graham cracker crumbs, melted butter, sugar, and salt.

Step 4: Press Crust into Pan. Press the crust mixture into the bottom and 1 inch up the sides of the springform pan.

Step 5: Bake Crust. Bake until golden brown, 10 to 12 minutes.

Step 6: Cool Crust. Cool completely on a wire rack, about 30 minutes.

Step 7: Prepare Water Bath. Bring a large pot of water to a simmer over medium-low heat.

Step 8: Make the Filling – Beat Cream Cheese. In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese on medium speed until no lumps remain, about 2 minutes.

Step 9: Add Remaining Filling Ingredients (Except Eggs and Vanilla). Gradually add the sour cream, sugar, flour, dill pickle powder, and salt, beating on medium speed until the batter is smooth and creamy, about 1 minute. Scrape down the sides and bottom of the bowl as needed.

Step 10: Add Eggs and Vanilla. Reduce the mixer to medium-low speed and add the eggs, one at a time, beating until just combined after each addition. Continue scraping down the sides and bottom of the bowl as needed. Stir in the vanilla, and key lime zest and juice (juice and zest the brined limes after removing them from the brine and drying them).

Step 11: Pour Filling into Crust. Pour the filling into the springform pan.

Step 12: Water Bath. Place the springform pan into a large roasting pan. Place both pans into the oven and quickly pour the hot water into the roasting pan so that it comes about halfway up the foil-wrapped springform pan.

Step 13: Bake. Bake for 1 hour 20 minutes to 1 hour 30 minutes or until the cheesecake is set on the sides and just barely jiggles in the center when the pan is shaken.

Step 14: Cool in Oven. Turn the oven off and crack the door. Leave the cheesecake in the oven for 15 minutes.

Step 15: Remove from Water Bath and Cool. Remove the cheesecake from the water bath and carefully remove the foil. Transfer to a wire rack. Let the cheesecake continue cooling to room temperature, about 2 hours.

Step 16: Chill. Place in the refrigerator for at least 8 hours to chill completely.

Step 17: Make the Topping. In the bowl of a stand mixer fitted with a whisk attachment, beat the cold heavy whipping cream until thickened. Add the sugar and vanilla; beat the cream on high until medium peaks form.

Step 18: Garnish and Serve. Run a thin knife along the edge of the pan before removing the sides from the pan. Top the cheesecake with the whipped cream, zest, and lime slices. Sprinkle with fresh dill, if using.