Preparation Steps

• Heat oven to 350°F. Line two baking sheets with parchment.
• Whisk flour, cocoa, baking soda, and salt in a bowl.
• Stir melted butter and granulated sugar in a large bowl until glossy.
• Beat in egg and 1 teaspoon vanilla, then mix in buttermilk.
• Fold dry ingredients into the wet just until combined; do not overmix.
• Scoop 1.5-tablespoon mounds onto sheets, spacing about 2 inches apart.
• Bake 8–10 minutes until edges look set. Cool on pans 5 minutes.
• Make icing: Warm butter, milk, and cocoa in a saucepan until steaming.
• Remove from heat. Whisk in powdered sugar and remaining 0.5 teaspoon vanilla until smooth.
• Spoon warm icing over warm cookies. Sprinkle pecans, then let set until firm.