Bars: Preheat the oven to 350 degrees F. Butter/spray a 9x13-inch baking pan. Line the bottom with parchment paper and butter/flour the parchment. Or line the entire pan with tin foil (have the foil go over the edges for easy removal) grease and flour the foil.
In a medium, heavy-bottomed saucepan, melt all the butter over low heat. Once the butter is melted, turn the heat up to medium and cook the butter until it turns golden brown and takes on a nutty fragrance. Depending on how high the heat is, this may take several minutes. Stir the butter occasionally and keep an eye on the color. it will get a little bit 'foamy' but keep cooking until it starts to clarify and then change to a golden brown. Once it has browned, remove it from the heat and let it rest for about 5 minutes.
In a medium bowl, whisk together the flour, baking powder, salt, and cinnamon. Set it aside.
In a separate, larger bowl mix the browned butter and sugar together with a large wooden spoon or spatula (the mixture will be grainy). Add the eggs, vanilla, and almond extracts. Mix well. Be sure the eggs have been well incorporated. Add the flour mixture and stir until thoroughly combined, scraping down the sides of the bowl as you stir. pour the batter into the prepared pan. it might be thick so you may have to spread it out with a spatula.
Bake for 30-40 minutes or until a toothpick inserted in the middle comes out slightly moist but with no crumbs. if the edges start to brown too much, remove the pan and cover just the edges with some tin foil. Once they are done, place the pan on a cooling rack and let it come to room temperature. you can serve these alone or with the butterscotch sauce.
Butterscotch: In a medium, heavy-bottomed saucepan, melt the butter over low heat. Add the sugar, cream, and salt. Whisk until blended. Bring the mixture to a slow, easy boil. Cook for about 5-10 minutes, stirring occasionally. *It will eventually begin to thicken. once it does, cook for about 2 more minutes.*
Remove from heat. As it cools, the butterscotch will thicken. You can pour it over the bars just before serving them or pour it on ahead of time.