3 cups (375g) all-purpose flour (spooned & leveled)

2 teaspoons cream of tartar*

1 teaspoon baking soda

1 and 1/2 teaspoons ground cinnamon

1/2 teaspoon salt

1 cup (16 Tbsp; 226g) unsalted butter, softened to room temperature

1 and 1/3 cup (267g) granulated sugar

1 large egg + 1 large egg yolk, at room temperature

2 teaspoons pure vanilla extract

1/3 cup (70g) granulated sugar

1 teaspoon ground cinnamon

2 and 1/4 cups (280g) all-purpose flour (spooned & leveled)

1 teaspoon baking soda

1 and 1/2 teaspoons cornstarch*

1/2 teaspoon salt

3/4 cup (170g / 12 Tbsp) unsalted butter, melted & cooled 5 minutes

3/4 cup (150g) packed light or dark brown sugar

1/2 cup (100g) granulated sugar

1 large egg + 1 egg yolk, at room temperature

2 teaspoons pure vanilla extract

1 and 1/4 cups (225g) semi-sweet chocolate chips or chocolate chunks

1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature

1 Tablespoon vegetable oil, avocado oil, or olive oil

1/2 cup (100g) granulated sugar

1/2 cup (100g) packed light or dark brown sugar

1 large egg, at room temperature

1 teaspoon pure vanilla extract

1 and 1/4 cups (156g) all-purpose flour (spooned & leveled)

1/2 cup (45g) unsweetened natural cocoa powder

1 teaspoon baking soda

1/8 teaspoon salt

3/4 cup (12 Tbsp; 170g) unsalted butter, softened to room temperature

2 cups (240g) confectioners’ sugar

6 Tablespoons (30g) unsweetened natural or Dutch-process cocoa powder

3 Tablespoons (45ml) heavy cream or milk, slightly warm (see Note)

1 teaspoon pure vanilla extract

pinch of salt

1/4 cup (43g) sprinkles (such as these or these)

1 and 3/4 cups (219g) all-purpose flour (spooned & leveled)

3/4 cup (62g) unsweetened natural cocoa powder

1 and 3/4 cups (350g) granulated sugar

2 teaspoons baking soda

1 teaspoon baking powder

1 teaspoon salt

2 teaspoons espresso powder (optional)

1/2 cup (120ml) vegetable oil (or canola oil or melted coconut oil)

2 large eggs, at room temperature

2 teaspoons pure vanilla extract

1 cup (240ml) buttermilk, at room temperature

1 cup (240ml) freshly brewed strong hot coffee (regular or decaf)

1 and 1/4 cups (282g) unsalted butter, softened to room temperature

3 and 1/2 cups (420g) confectioners’ sugar

3/4 cup (65g) unsweetened cocoa powder (natural or dutch process)

3–5 Tablespoons (45-75ml) heavy cream (or half-and-half or milk), at room temperature

1/4 teaspoon salt

1 teaspoon pure vanilla extract

optional for decoration: semi-sweet chocolate chips

1 cup (240ml) whole milk, warmed to about 100°F (38°C)

6 Tablespoons (75g) granulated sugar, divided

1 Tablespoon (9g) active dry or instant yeast

5 Tablespoons (71g) unsalted butter, melted and slightly cooled

2 large eggs, at room temperature

1 teaspoon salt

4 cups (530g) bread flour (spooned & leveled), plus more as needed for hands/work surface

6 Tablespoons (85g) unsalted butter, softened to room temperature

1/2 cup (100g) packed light or dark brown sugar

2 Tablespoons (10g) unsweetened natural or dutch process cocoa powder

1 teaspoon ground cinnamon

1 teaspoon pure vanilla extract

3/4 cup (135g) semi-sweet chocolate chips or a 4 ounce semi-sweet chocolate bar, finely chopped*