4 squares (1 ounce each) white baking chocolate, chopped
Heat oven to 350 degrees F. Line a baking sheet with aluminum foil or waxed paper.
Spread hazelnuts on a jelly-roll pan and toast 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 prepared baking sheet. Gently loosen open edge; insert a hazelnut or pistachio in center of each apricot. Press edges together to seal. Keep hazelnut-and pistachio-stuffed apricots seperate.
Place 3 squares semisweet chocolate in a small microwave-safe bowl. Cover with plastic wrap. Microwave at 100% power 1 minute. Stir until smooth. Stir in remaining semisweet chocolate until well blended and smooth.
Using a fork, spear a hazelnut-stuffed apricot; 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. Repeat with remaining hazelnut-stuffed apricots. Set aside remaining semisweet chocolate.
Repeat steps 4 and 5, substituting white chocolate and the pistachio-stuffed apricots.
Refrigerate coated apricots 3 hours or until chocolate is firm.
Microwave remaining semisweet chocolate at 50% power 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 in an airtight container in a cool, dry place up to 1 week.