Heat oven to 350 degrees F. Toast hazelnuts on jelly-roll pan in oven about 10 minutes or until lightly golden. When hazelnuts are cool enough to handle but still warm, rub lightly between paper toweling to remove skins; discard skins.
Place apricots on foil- or waxed-paper-lined baking sheet. Gently loosen open edge; insert hazelnut or pistachio in center of each apricot. Press edges together to seal.
In small microwave-safe bowl, place 3 ounces semisweet chocolate. Cover with plastic wrap. Microwave at full power for 1 minute. Stir until smooth and blended. Stir in remaining semisweet chocolate until well blended and smooth.
Using a fork, spear hazelnut-stuffed apricots; dip into melted semisweet chocolate, turning to coat completely; shake off excess chocolate by gently tapping fork on edge of bowl. Return to baking sheet. Set aside remaining semisweet chocolate.
Repeat Steps 3 and 4, substituting white chocolate and the pistachio-stuffed apricots.
Refrigerate coated apricots 3 hours or until chocolate is firm.
Microwave remaining semisweet chocolate at 50 per cent power for 30 seconds, or until drizzling consistency. Drizzle over white-chocolate-coated apricots. Refrigerate on baking sheets to harden. Repeat with reserved white chocolate; drizzle over semisweet-coated apricots. Store airtight in cool, dry place. Makes 24 candies.