Preheat oven to 350 degrees F. Line a loaf pan with parchment and/or butter sides.
In the bowl of your stand mixer with the paddle attached, combine flour, baking powder, salt, pumpkin pie spice, and sugar. Add softened butter and mix on low speed until all of the dry ingredients are coated with the butter - not mixed into a dough, but it holds its shape when pinched together.
Combine eggs, vanilla, and eggnog in a separate container. Add about half of this liquid mixture to the flour mixture and mix on medium high speed for 3-5 minutes until very light and fluffy. Scrape sides. Add remaining liquid mixture and mix on low until well incorporated.
Spoon batter into prepared loaf pan and bake in preheated oven for 50-55 minutes, until toothpick inserted in center comes out clean. Take care not to overcook, else it will taste dry. Remove from cake pan and allow to cool fully on rack.
For the glaze, whisk together egg nog and powdered sugar, adding egg nog until desired consistency. Spoon over cooled cake. Sprinkle with crushed candied pecans. Let glaze set up for a few hours before serving or storing.