• Adjust top oven rack to lower-middle position while also making sure there is room under that rack for a shallow pan of water. Heat oven to 400°F degrees.

For the Graham Cracker Crust:

• Process graham cracker crumbs until fine, add brown sugar and process to incorporate well. In medium bowl; add processed crumbs with 6 tablespoons melted butter and toss with fork until evenly moistened.
• Brush bottom of 10 1/2-inch springform pan with additional melted butter. Pour crumbs into springform pan and press evenly into pan bottom. Bake until fragrant and beginning to brown around edges, 6-8 minutes. Cool on wire rack while making filling.
• While preparing the filling, increase oven temperature to 500°F degrees and bring 2 cups of water to a boil in a kettle or pan on the stove for the steam pan you'll position on the lowest rack under the cheesecake.
• Once boiling, pour the water into a 9x13 pan and carefully place the pan on the lowest rack of the oven, just under the rack for the cheesecake. (This is optional, however it will help prevent the cheesecake from cracking while baking. It will not affect the quality of the cheesecake, only the appearance.)

For the Cheesecake Filling:

• In a mixer, beat cream cheese at medium speed to break up and soften slightly, about 1 minute. Scrape beater and sides of bowl well after each add-in to be sure all the ingredients are well incorporated.
• Mix-in salt and sugar; beat at medium-low speed until combined. Add sour cream, 1 tablespoon lemon juice, all the zest, and vanilla; beat at low speed until well mixed.
  
• Add egg yolks and beat at medium-low speed until combined, then add remaining whole eggs two at a time, beating until thoroughly combined and smooth, scraping bowl and beaters between additions.
• Just above the crust edges, brush sides of springform pan with melted butter. Set springform pan on rimmed baking sheet to catch any pan leaks. Pour filling into pan and bake 10 minutes.
• Then reduce oven temperature to 200°F degrees (don't open the oven door) and continue to bake until an instant-read thermometer inserted into the center of cheesecake registers 150°F degrees, about 1 and 1/2 hours (check at 1 hour, 15 minutes).
• Remove from the oven and run a paring knife around the inside of pan to make sure the cake releases from the sides (this will help prevent it from cracking as it cools).
• Cool completely in the pan on a wire rack, 2 1/2 to 3 hours so the cheesecake is no longer warm at all before cooling in the refrigerator. Wrap tightly (in the pan) with plastic wrap and refrigerate until cold, at least 3 hours (or overnight).

For the Blueberry Topping:

• Reserve 1/2 cup of blueberries for garnish. In a small saucepan over medium-high heat stir together the sugar, cornstarch, water, lemon juice, and lemon zest. Cook over medium heat, stirring until thickened, about 5 minutes.
• Stir in blueberries and simmer the mixture, stirring occasionally, until the berries break down, 5-8 minutes. Add the butter and stir until melted. Remove from heat and let cool before serving with the cheesecake. Yields 3 cups. (Taste can be adjusted by adding more lemon if too sweet.)

Serving the Cheesecake:

• Remove from the refrigerator and let the cheesecake stand at room temperature about 30 minutes before serving. To unmold the cheesecake, run a paring knife around inside of pan then remove the ring of the springform pan. Slide a thin metal spatula between crust and pan bottom to loosen.
• When cutting the cake into wedges, wipe the knife clean after each cut to make neat slices. To serve, dress each piece with Blueberry Topping and fresh blueberries.