Ingredient:

• 10 tablespoons butter
• 1-1/4 cups sugar
• 1 cup baking cocoa
• 1/4 teaspoon salt
• 1/2 teaspoon instant espresso powder
• 1 teaspoon vanilla extract
• 2 large eggs, room temperature
• 1/2 cup all-purpose flour
• 3/4 cup dark chocolate chips or chunks