In a medium saucepan, melt butter over medium heat. Add pecans and cook, stirring often until fragrant, about 4 minutes. Add both sugars, maple syrup and heavy cream, stirring until well combined. Cook for 7-8 minutes until thickened. Remove from heat and stir in vanilla.
Pecan Waffles
Preheat oven to 350 degrees. Spread 1/2 cup pecans on a baking sheet, and toast in oven for 5-7 minutes until fragrant. When cooled, finely chop. Set aside. Lower oven temperature to 250 degrees.
Preheat waffle iron. In a large bowl, whisk together flour, sugar, baking powder and salt until well combined. Set aside.
In a small bowl, whisk together milk, eggs, vanilla and butter. Add wet ingredients to dry ingredients until just combined. Do not over mix. Add pecans. It's ok to have a few lumps.
Spray iron with non-stick cooking spray. Fill iron according to manufacturer's instructions. Cook until golden brown. Transfer finished waffles to oven and place directly on oven rack to keep warm until finished with all the batter. Serve topped with warm pecan praline sauce.