Preheat your oven to 375 and prep your donut pan by lightly spraying or coating with butter or vegetable oil.
Brown your stick of butter along with your sage leaves in a small saucepan set over medium heat. Stir frequently until butter begins to brown, about 4-6 minutes. This will happen slowly at first, and then very quickly it will turn and brown, so keep an eye on it and take it off the heat as soon as it browns and releases a nutty aroma. The sage butter will not impart much of a flavor into the donuts, but will definitely be noticeable in the glaze. Skip the sage if you aren't partial to the flavor. Strain sage and pour butter into a measuring cup.
Combine flour, baking powder, salt and pumpkin pie mix in a medium bowl.
Mix together sugar and eggs in a large bowl until light and fluffy, then stir in the canned pumpkin and vanilla.
Add the flour mixture and ½ of the brown butter, about ¼ cup, to the egg mix and stir just to combine, making sure not to over-stir.
For best formed donuts, I recommend piping them out as opposed to spooning the mix into the donut pan, but you do you. If you're piping, go ahead and add donut mix to the piping bag and cut out a large hole at the tip.
To get nice full and fluffy donuts, pipe in the donut mix in an even motion and fill completely. Many recipes say to fill just ¾ way full but this yields puny looking donuts, so go ahead and fill completely.
Bake for 8-10 minutes until a cake tester comes out clean. Remove from oven and let cool in pan a couple of minutes before removing from donut mold and transferring to a cooling rack.
For the glaze, heat the remaining brown butter back up in a small sauce pan over medium low heat, and stir in the maple syrup. Remove from heat and sift in powdered sugar and whisk to combine completely to get a nice smooth glaze. Don't skip the sifting unless you want your glaze to crack a bit. I skipped the first time and my glaze came out much prettier after sifting.
Spoon glaze over each cooled donut, working quickly as glaze will begin to cool after a few minutes and lose its pretty sheen. Top with chopped pecans, or if you're feeling really wild, top with sugared pecans.