FOR BROWNIE CUPS:
PREHEAT oven to 350° F. Lightly coat 12 mini muffin cups with cooking spray. (If 2 pans [24 cups] are available, coat cups with nonstick spray and prepare 2 pans at a time.)
MELT 1 1/2 cups morsels, butter and Choco Bake in medium saucepan over low heat, stirring constantly until morsels are melted. Remove from heat. Stir in granulated sugar. Add eggs, one at a time, beating with a wooden spoon after each addition just until combined. Stir in 3/4 teaspoon vanilla extract. Stir in flour just until combined. Spoon rounded tablespoon of batter into each prepared muffin cup, filling each about 3/4 full. Cover and refrigerate remaining batter while baking the first batches.
BAKE brownies for 12 minutes. Cool for 15 minutes in muffin cups on wire racks. Make an indentation into the top of each brownie with the handle of a wooden spoon. Remove brownies from muffin cups to cool completely on wire racks. Wipe out muffin cups; lightly coat with cooking spray and repeat with remaining batter, using a total of four 12-cup pans.
FOR PEANUT BUTTER FILLING:
BEAT peanut butter, powdered sugar, cream cheese, milk and 1/2 teaspoon vanilla extract in medium mixer bowl until light and fluffy. Transfer mixture to a resealable plastic bag. Seal bag; snip off a small corner. Pipe peanut butter mixture into the indentation in each brownie.
PLACE remaining 1/2 cup morsels in small, havy-duty plastic bag. Microwave on HIGH (100%) power for 30 to 45 seconds; knead. Cut a tiny corner from bag and drizzle over tops of bonbons. Store in airtight container in refrigerator.