Prepare the Crust: Heat 1/2 tablespoons of the melted butter in a small skillet over medium; add chopped pecans, and cook, stirring constantly, until toasted, 3 to 4 minutes. Remove from heat, and let cool completely, about 20 minutes. Finely chop toasted pecans.

While pecans cool, preheat oven to 325°F. Wrap outside (bottom and sides) of a 9-inch springform pan with heavy-duty aluminum foil; coat inside (bottom and sides) of pan with cooking spray. Stir together graham cracker crumbs, brown sugar, cooled toasted pecans, and remaining 6 tablespoons melted butter in a medium bowl. Press crumb mixture on bottom and 1-inch up sides of prepared pan. Bake in preheated oven until crust is set and lightly browned, 7 to 8 minutes. Transfer to a wire rack; let cool completely, about 30 minutes.

Prepare the Filling: Beat cream cheese in bowl of a heavy-duty stand mixer fitted with a paddle attachment on medium speed until creamy, 2 to 3 minutes. Gradually add sugars and flour, beating until smooth, about 1 minute. Add whole eggs, 1 at a time, beating just until incorporated after each addition. Add egg yolks, 1 at a time, beating just until incorporated after each addition. Beat in heavy cream and vanilla on low speed just until combined, about 1 minute. Pour filling over crust in prepared pan (it will be full).

Place springform pan in a roasting pan. Place roasting pan on oven rack, and carefully pour in boiling water to reach halfway up sides of springform pan. Bake in preheated oven until center is almost set and jiggles slightly, 1 hour and 10 minutes to 1 hour and 20 minutes. Transfer to wire rack; remove aluminum foil. Let cheesecake cool until slightly warm, 1 1/2 to 2 hours.

Prepare the Topping: Bring brown sugar, butter, cream, and salt to a boil in a small saucepan over medium. Cook, stirring constantly, until thickened, 2 1/2 to 3 1/2 minutes. Stir in pecan halves and pieces. Remove from heat, and let stand 5 minutes, stirring occasionally.

Spoon warm topping evenly over slightly warm cheesecake, leaving about a 1/2-inch border around edges. Let stand until pecan mixture is set, about 30 minutes. Coat a piece of foil with cooking spray, and cover cheesecake; chill at least 8 hours or up to 24 hours. Run a knife around outer edge to loosen cheesecake from sides of pan; remove sides of pan.