In a large skillet, melt the 1 1/2 Tbsp of butter over medium heat. Add in chopped pecans and cook, stirring occasionally, for 4 to 5 minutes until lightly toasted. Set aside until needed.

In a large bowl,  whisk the flour, cornstarch, salt, cinnamon, and baking soda together until combined.

Brown the butter by melting the butter in a heavy bottom pan over medium-low heat. (see how in notes)

Remove pan from heat and pour butter into a large, heatproof mixing bowl. Add in both sugars and vanilla, whisk to combine.

Beat in eggs, one at a time, beating until eggs are just combined.

Using a rubber spatula, fold in the flour mixture, stirring until just combined. Fold in the buttered pecans.

Cover bowl and refrigerate for at least 2 hours, and up to 2 days. You want the dough to be firm, but scoopable. If you refrigerate for more than 2 hours, you'll need to let the dough sit at room temperature until it's scoopable.

Flatten dough slighty to be more of a disc shape. The gently press your thumb into the top of the disc making a slight indentation. Place a pecan half into each of the indetations.

Bake at 375 degrees for 9 minutes, or until lightly browned and edges are set but the center is still a little soft. Sprinkle warm cookies with a little granulated sugar. Allow  to cool on the baking sheet for 15 minutes, then carefully transfer to a cooling rack. Repeat with remaining cookie dough.