4 oz unsweetened chocolate, chopped
1/4 cup unsalted butter
1 1/2 cups all-purpose flour
1 cup Dutch-process cocoa powder
2 teaspoons baking powder
1/4 teaspoon salt
4 large eggs
2 cups granulated sugar
1 teaspoon vanilla extract
1 teaspoon ground cinnamon
1 cup miniature semisweet chocolate chips
1/2 cup confectioners’ sugar (for coating)
Place the chocolate and butter in the top of a double boiler placed over (not touching) barely simmering water. Heat, stirring often, until the butter and chocolate melt. Remove from over the water and set aside to cool slightly. In a bowl, stir together the flour, cocoa powder, baking powder, and salt. Set aside.
Mixer: In a large bowl, combine the eggs, granulated sugar, and vanilla. Beat on medium speed until light in color and thick, about 3 minutes. Beat in the melted chocolate mixture on low speed until blended. Add the dry ingredients and beat until incorporated. Mix in the chocolate chips.
Cover the bowl with plastic wrap and refrigerate until the dough is firm enough to roll into balls, about 2 hours.
Bake at 325 degrees on parchment paper.
To form each cookie, roll a rounded tablespoon of dough between your palms into a 1 1/2 inch ball (I make them mini-size since they are so dense), and roll the ball in the confectioners’ sugar. Place the cookies 3 inches apart on the prepared baking sheets. Make sure to set them firmly into the baking sheet so they stay into place.
Bake the cookies, 1 sheet at a time, until the tops are puffed and crinkled and feel firm when lightly touched, 13-17 minutes. Let the cookies cool on the baking sheet for 5 minutes, then transfer the cookies to wire racks to cool completely. Store in an airtight container at room temperature for up to 3 days.