1 3/4 cup plus 2 Tbs. (9 1/2 oz./280 g) all-purpose flour
1 1/2 tsp. baking powder
1/2 tsp. salt
8 oz. (250 g) semisweet chocolate, finely chopped
2 3/4 cups (22 oz./690 g) granulated sugar
1/4 cup (2 fl. oz./60 ml) canola oil
3 Tbs. unsalted butter, melted and kept warm (but not hot)
2 Tbs. light corn syrup
1 egg yolk
2 tsp. vanilla extract
1 1/2 tsp. peppermint extract
1 cup (4 oz./125 g) confectioners’ sugar
In a bowl, stir together the flour, baking powder and salt; set aside.
In a microwave-safe bowl, melt the chocolate in a microwave oven set at 50% power until softened but not fully melted, about 1 minute. Stir and microwave for 15 seconds more. The chocolate should be uniformly melted. If it isn’t, continue to microwave in 15-second increments, stirring after each time. Set aside.
In a stand mixer fitted with the flat beater on medium speed, beat together 2 1/2 cups (20 oz./625 g) of the granulated sugar, the oil, butter and corn syrup until blended. Beat in the eggs, egg yolk, vanilla and peppermint extract. On low speed, beat in the melted chocolate. Add the flour mixture and beat in on low speed.
Divide the dough into 4 equal pieces, wrap each piece in plastic wrap and refrigerate for several hours or overnight.
Preheat an oven to 325°F (165°C). Line a baking sheet with parchment paper.
Put the remaining 1/4 cup (2 oz./60 g) granulated sugar in a shallow bowl. Put the confectioners’ sugar in a separate shallow bowl.
Remove one of the pieces of dough from the refrigerator. Roll the dough into balls about 3 inches (7.5 cm) in diameter. Roll each dough ball in the granulated sugar to lightly coat, then roll in the confectioners’ sugar until it is heavily coated.
Arrange the cookies 2 inches (5 cm) apart on the prepared baking sheet. Bake for 10 to 12 minutes for chewy cookies, or up to 14 minutes for crisper cookies. Remove from the oven and let the cookies cool for 1 to 2 minutes, then press the cookies flat with a spatula. Repeat with the remaining ingredients.
Transfer the cookies to a wire rack and let cool completely. Makes 2 dozen cookies.