To make the crust, preheat the oven to 350 degrees F. Grease a 9x13 inch baking pan. Line the bottom of the pan with aluminum foil, and lightly grease the foil. Set aside.
In the bowl of a food processor, combine the flour, sugar, and salt. With the machine running, add the butter pieces and continue to process until the mixture resembles very fine, moist crumbs. The mixture won't come completely together in the processor.
Turn the crumbs out onto the prepared baking sheet and using your hands, gently press to form a smooth, even layer. Bake until the crust is a light golden brown, 30 to 35 minutes. Set aside.
While the crust is baking, combine the butter, brown sugar, maple and corn syrups in a saucepan. Heat over medium heat, stirring constantly, until the butter has melted and the mixture is completely combined and smooth. Cook one additional minute, then remove from heat and set aside.
In a large mixing bowl, whisk together the eggs, cream, vanilla and salt. Slowly whisk in about 1/4 cup of the warm sugar mixture to temper the eggs. Slowly whisk in another 1/4 cup, then slowly stir in the rest. When fully combined, stir in the pecans.
Pour the pecan mixture over the prepared crust. Return to the oven and bake until the pecan mixture is bubbling and jiggles when gently tapped, an additional 20 to 25 minutes.
Remove from the oven and place the sheet on a rack to cool completely. Lift the foil from the sheet to get the bars out of the pan. Cut into squares. Store in an airtight container.