Preheat oven to 300°F (150°C).

Spread the pecans on a lined baking sheet and bake for 8–10 minutes. Let cool for a few minutes, then chop, either with a knife or a food processor. You’ll use 3/4 cup (about 90g) in the dough, and save the rest for garnish. You can turn off the oven for now.

Whisk the flour, baking powder, cinnamon, and salt together in a medium bowl. Set aside.

In a large bowl using a handheld or a stand mixer fitted with a paddle attachment, beat the butter and brown sugar together on high speed until completely smooth and creamy, about 3 minutes. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the egg, and vanilla, and beat on high speed until combined, about 1 minute. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine.

Add the dry ingredients to the wet ingredients and mix on low until combined. Stir in 3/4 cup (90g) toasted chopped pecans. Dough will be a bit soft. If the dough seems too soft and sticky for rolling, add 1 more Tablespoon of flour.

Divide the dough into 2 equal parts. Place each portion onto a piece of lightly floured parchment paper or a lightly floured silicone baking mat. With a lightly floured rolling pin, roll the dough out to about 1/4-inch thickness. Use more flour if the dough seems too sticky. The rolled-out dough can be any shape, as long as it is evenly 1/4-inch thick.

Lightly dust one of the rolled-out doughs with flour. Place a piece of parchment on top. (This prevents sticking.) Place the second rolled-out dough on top. Cover with plastic wrap or aluminum foil, then refrigerate for at least 1–2 hours and up to 2 days.

Once chilled, preheat oven to 350°F (177°C). Line 2–3 large baking sheets with parchment paper or silicone baking mats. Carefully remove the top dough piece from the refrigerator. If it’s sticking to the bottom, run your hand under it to help remove it. Using a cookie cutter, cut the dough into shapes. Re-roll the remaining dough and continue cutting until all is used. Repeat with second piece of dough. (Note: It doesn’t seem like a lot of dough, but you get a lot of cookies from the dough scraps you re-roll.)

Arrange cookies on baking sheets about 3 inches apart. Bake for 12–13 minutes or until lightly browned around the edges. If your oven has hot spots, rotate the baking sheet halfway through bake time. Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely before decorating. No need to cover the cookies as they cool.

Slice the butter up into pieces and place in a light-colored skillet. (Light colored helps you determine when the butter begins browning; I love this one.) Melt the butter over medium heat, stirring constantly. Once melted, the butter will begin to foam. Keep stirring. After 5–8 minutes, the butter will begin browning—you’ll notice lightly browned specks begin to form at the bottom of the pan and it will have a nutty aroma. Once browned, immediately remove from heat and cool for 5 minutes. (See How to Brown Butter for photos and tips.) Whisk in the remaining icing ingredients until smooth.

Immediately dip the top of each cookie into the icing, or wait 10–15 minutes for the icing to thicken at room temperature. (The thickened icing is what you see in these photos.) Then, spread on with a knife or icing spatula. Do not use piping tips because this icing thickens and they will clog. Garnish with remaining toasted chopped pecans right after applying the icing.

Icing sets after a few hours at room temperature, so you can easily stack and transport these cookies. Cover and store decorated cookies for up to 3 days at room temperature or up to 10 days in the refrigerator.