Preheat oven to 350 degrees F.
Meanwhile, remove ice cream from freezer and let stand at room temperature or at least 15 minutes to soften.
Remove nuts from the oven and let cool. Turn off oven.
In each of the glasses, put about 2 tablespoons caramel or butterscotch sauce in bottom. Top with a layer of softened ice cream, packing it down slightly and being careful not to smear the sides of the glass too much (if you do smear glass while making layers, wipe down inside with paper towels as you work). Sprinkle with a teaspoon or so of pecans. Continue layering in the same fashion: sauce, ice cream, pecans until you reach the top of the glass. Make the last layer sauce and sprinkle it with pecans.