Instructions

for the cookies

Adjust oven racks to upper-middle and lower-middle position and heat oven to 350 degrees. Line 2 rimmed baking sheets with parchment paper.
Microwave 3 ounces finely chopped unsweetened chocolate and 3 tablespoons unsalted butter (cut into 6 pieces) in small bowl at 50 percent power, stirring occasionally until melted, 1 to 2 minutes. Whisk 1¾ cups (8¾ ounces) all-purpose flour, ½ cup (1½ ounces) unsweetened cocoa powder, ¾ teaspoon baking powder, ¼ teaspoon baking soda, and ½ teaspoon table salt together in large bowl until evenly combined. Whisk 1 cup (7 ounces) packed light brown sugar, ¼ cup (1¾ ounces) granulated sugar, and 2 large eggs together in second large bowl until fully incorporated.
Whisk ⅓ cup sour cream, 1 teaspoon vanilla extract, and chocolate mixture into brown sugar mixture. Add flour mixture and stir until no dry streaks of flour remain. Cover bowl and refrigerate until chilled, at least 2 hours (dough can be refrigerated up to 2 days).
Divide dough into 24 portions, about 2 tablespoons each. Roll dough portions between your wet hands to form balls (mixture will be sticky).  Divide portions between prepared sheets, 12 per sheet.
Bake until cookies are puffed and cracked and set at edges (cookies may seem underdone between cracks), 10 to 12 minutes, switching racks and rotating baking sheets front to back halfway through.
Transfer baking sheets to wire racks. Working quickly, use rounded 1-teaspoon measuring spoon to make indentation in center of each cookie. Fill indentions in each cookie with heaping ½ teaspoon apricot jam.  Let cookies cool completely.

for the glaze

Combine 1 cup (7 ounces) granulated sugar and ⅓ cup water in microwave-safe 2-cup liquid measuring cup. Microwave until bubbling all over, about 2 minutes. Stir until sugar is dissolved, about 30 seconds, then stir in 1 cup (6 ounces) bittersweet chocolate chips. Microwave at 50 percent power, stirring occasionally, until chocolate is fully melted and mixture runs easily from back of spoon, about 1 minute longer.
Place all cookies on 1 wire rack set in rimmed baking sheet. Pour glaze over cookies to fully coat. If needed, use bench scraper to scrape excess glaze from sheet back into measuring cup; return to microwave and microwave at 50 percent power for 10 seconds at a time until mixture drizzles easily from back of spoon. Continue until all cookies are coated.
Transfer tray of cookies to refrigerator until glaze is set, about 1 hour. Serve.