Melt the butter in a small pot and gently whisk occasionally. Watch for the butter to start browning on the bottom of the pot, and whisk continuously as it browns. Remove from heat once it smells nutty, and there are some brown bits in the bottom of the pan.

Pour into a heat-safe bowl and let cool for 30 minutes at room temperature. The butter should be slightly warm or at room temperature.

In a large bowl, stir brown butter, brown sugar, and sugar together until smooth.

Stir in egg, vanilla, and molasses, then stir in pumpkin puree.

Add all dry ingredients and stir until the dough comes together.

Scoop cookies with a heaping 1 1/2 TBS cookie scoop (or use a level 2 TBS scoop). Weigh the dough (weighing is optional but makes for consistent-sized cookies). Each ball of dough should weigh 28-29 grams.

Roll each dough ball between your hands to smooth the surface, and place the dough on a lined cookie sheet. Cover and refrigerate for at least 2 hours or overnight.

Preheat oven to 350 F / 175 C and remove cookies from the refrigerator.

Combine the 50 grams of sugar and 2 teaspoons of cinnamon in a bowl and roll the balls of cookie dough in the cinnamon sugar right before baking.

Bake on parchment-lined half sheet pans for 10-12 minutes.

Cookies are done when they look slightly dry on top but still somewhat moist in the cracks.

Transfer cookies to a cooling rack. Eat warm or cool, and store in a container for up to a week.