Updated Nov 18, 2019Chatelaine
1. Cut 4 sheets of parchment to fit a large baking sheet. Have 2 large baking sheets at the ready. Beat butter with sugar, 3/4 cup cocoa powder and salt in a large bowl, using an electric mixer on medium-low, until fluffy, 2 to 3 min. Beat in egg and vanilla. Reduce speed to low, then gradually beat in 1 1/4 cups flour until just combined. Divide dough in half, then form each into a log.
2. Stir 1 tbsp each cocoa powder and flour in a medium bowl. Coat 1 log with cocoa mixture and place on a parchment sheet. Top with another parchment. Roll dough between parchment until 1/8 in. thick. Transfer parchment and dough onto 1 baking sheet. Repeat with remaining piece of dough and parchment. Transfer to same baking sheet, stacking on top of other. Refrigerate until dough is firm to the touch, about 1 hr.
3. Position rack in centre of oven, then preheat to 325F. Remove 1 sheet of dough from refrigerator. Peel off top parchment and use it to line other baking sheet. Cut out circles with a 3-in. round fluted cookie cutter. Transfer cookies to prepared sheet, about 1 in. apart.
4. Remove baking sheet from refrigerator and slide remaining sheet of dough onto counter. Peel off top parchment and use to line baking sheet. Cut out rounds, then transfer to prepared sheet. Refrigerate both sheets until dough is firm, 10 to 15 min. Using smaller 1-in. holiday-shaped cookie cutters, cut out shapes from centre of half the rounds and remove. Bake until cookies look dry, 9 to 10 min. Let stand on sheet for 5 min, then transfer to a rack to cool completely. Meanwhile, gather dough scraps and form into a log. Repeat rolling, cutting and baking process.
5. When cookies are cool, preheat oven to 400F. Spray the underside of a flat, metal spatula with oil. Working in 2 batches, arrange solid cookies on a baking sheet, bottom-side up. Cut marshmallows in half, crosswise, with scissors. Fill a small bowl with water. Dip cut-side of each marshmallow in water, then place on cookies, wet-side up.
6. Bake until marshmallows start to soften and turn light golden around the edges, about 2 min. Remove sheet from oven, then immediately use the oiled spatula to press down on marshmallows to flatten (the oil prevents the marshmallows from sticking to the spatula). Top with cookies that have the centre cut-out, gently pressing down. Transfer to rack to cool completely. Brûlée marshmallows with a torch, if desired.
Placing marshmallows wet-side up on cookies will keep the cut-outs smooth when brûléed. When brûléeing, keep the cookies on a wire rack. Avoid holding them to prevent burning yourself.
You can also bake the small cut-outs as mini chocolate cookies. After cutting out the centres, transfer the mini cookies to another parchment-lined baking sheet. Bake until crisp, 5 to 7 min.
Cookies will keep well stored in a covered container up to 3 days.