For the pudding, in a medium saucepan, combine sugar, salt, and flour. Slowly stir milk into dry mixture. Place over medium-high heat and cook, stirring continuously, until the mixture is simmering and begins to thicken. Remove from heat.

Meanwhile, use a whisk to beat egg yolks in a small bowl. Briskly whisk in a small amount of the hot milk mixture (about ½ cup), then pour the tempered egg yolk mixture into the remaining milk mixture, whisking continuously. Add the butter, vanilla and, if using, vanilla bean seeds, and whisk to combine. 

Return the saucepan to the stove over low heat, then cook, stirring continuously with a wooden spoon, until the mixture becomes thick, about 5 minutes. Remove from heat and set aside.

For the candied pecans, toast the pecans in a dry nonstick skillet over medium heat until fragrant, 2 to 3 minutes. Add the maple syrup and sprinkle with sugar, then stir to combine and season with salt. Once sugar dissolves, remove from heat and let cool completely.

To assemble the Pecan Pie Pudding, in decorative glasses for individual portions or a serving bowl, top a thick layer of pudding with the candied pecans.