Put 6 tablespoons of butter in a saucepan and heat over medium heat. Cook the butter until the foaming and bubbling subsides and the solids start to brown, stirring occasionally. Take the butter off heat and continue to stir until the solids are an even brown (not too dark). If you're afraid of burning the butter, err on the side of caution. Add the remaining 2 tablespoons of butter to stop the cooking. Set aside to cool.
In a separate bowl, whisk together the flour, spices, lemon zest, baking soda and salt until evenly combined.
When the butter is cool, stir in the brown sugar, molasses, egg, and vanilla. Whisk to evenly combine. Add the dry ingredients and mix until no streaks of flour remain.
Preheat the oven to 350 degrees F. Chill the dough for 15 - 30 minutes or until you can handle it without the dough sticking too much to your hands.
In a shallow bowl, add roughly 1/4 cup of granulated sugar.
Take roughly 1 1/2 tablespoons of dough and roll it into a ball then roll it in the bowl of sugar to cover. Place on baking sheet. Space the cookies 2 inches apart. Flatten them with the bottom of a drinking glass until they are between 1/4 inch and 1/2 inch thick. For chewy cookies, bake at 350 degrees for 10 - 12 minutes or until the edges are cooked but the center is still soft. Bake longer if you want crispy cookies.