¼ cup semisweet chocolate chips (such as Ghiradelli® 60% Cacao)
1 ⅛ cups all-purpose flour
3 tablespoons unsweetened baking cocoa (such as Ghirardelli®)
1 teaspoon baking powder
1 teaspoon ground cinnamon (Optional)
¼ teaspoon baking soda
½ teaspoon salt
½ cup unsalted butter, softened
⅓ cup white sugar
1 large egg, room temperature
1 ½ teaspoons vanilla extract
¼ cup buttermilk, at room temperature
5 tablespoons unsalted butter
5 tablespoons heavy cream
3 tablespoons unsweetened baking cocoa (such as Ghirardelli®)
1 teaspoon vanilla extract
¼ teaspoon salt
2 cups powdered sugar
Method
Melt chocolate chips in a double boiler over simmering water, stirring often and scraping the sides to prevent burning, for about 5 minutes. Let the melted chocolate cool down.
Heat your oven to 350°F (175°C).
In a bowl, whisk together flour, cocoa powder, baking powder, cinnamon, baking soda, and salt until well mixed. Set this mixture aside.
In a separate bowl, cream together butter and sugar using an electric mixer until fluffy and light. Add in the egg and vanilla extract, mixing until fully combined. Then, incorporate the cooled chocolate until blended. Gradually add half of the dry ingredients, mixing until just combined, followed by the buttermilk. Finally, mix in the remaining dry ingredients until just combined.
Use a medium cookie scoop to drop balls of dough onto lined baking sheets, spacing them about 1.5 inches apart.
Bake the cookies in the preheated oven for 8 to 10 minutes, or until they are just set. Avoid overbaking. Once done, take them out and let them cool slightly on the baking sheets without removing them.
For the frosting, combine butter, heavy cream, cocoa powder, vanilla extract, and salt in a saucepan over low heat. Whisk until the butter melts and the mixture is smooth. Gradually mix in powdered sugar, one cup at a time, ensuring thorough blending after each addition. Continue whisking on low heat until the frosting is glossy and smooth, about 1 to 2 minutes.
Once the frosting is ready, remove it from heat and immediately pour about 1 to 2 tablespoons over each warm cookie, using the back of a spoon to spread it as needed. Let the cookies cool completely so the frosting can set before gently lifting them off the baking sheets.
