Preheat oven to 350ºF. Line a 9-by-13-inch baking pan on bottom and 2 long sides with a sheet of heavy-duty aluminum foil, making sure that foil is smooth and overhangs top of pan by at least 4 inches on both sides. Mist foil with cooking spray.
Make crust: Combine flour, confectioners' sugar and salt in a food processor and pulse once or twice. Add butter and process until dough forms a clump when squeezed, about 30 seconds. Sprinkle mixture across bottom of pan and press into an even layer, making sure there are no cracks. Bake crust until it looks dry, 18 to 20 minutes. Place on a wire rack.
Make filling: Reduce oven temperature to 325ºF. Combine honey, brown sugar and salt in a saucepan and bring to a simmer over medium heat, stirring to dissolve sugar. Reduce heat and simmer for 2 minutes without stirring. Add butter and cream and simmer, stirring constantly, for 1 minute. Remove from heat; stir in pecans.
Pour hot filling evenly over crust. Use back of a spoon to distribute nuts evenly. Return pan to oven and bake until filling is bubbling and slightly browned, 18 to 20 minutes. Transfer pan to a wire rack and cool completely. Run a small knife between pan and pastry on sides without foil. Lift foil from pan onto a cutting board and use a serrated knife to cut into 30 diamonds.