Shuck oysters, discarding shells, and place oysters in a single layer in a 13- x 9-inch pan. (Pre-shucked oysters work well for this. Reserve 2 Tbsp. oyster liquor.)

Preheat broiler with oven rack 6 inches from heat. Melt 2 Tbsp. butter with 2 Tbsp. olive oil in a large skillet over low heat; stir in breadcrumbs and next 9 ingredients. Remove from heat.

Microwave remaining 2 Tbsp. butter and 2 Tbsp. olive oil in a small microwave-safe bowl at HIGH 20 seconds or until butter melts. Stir in reserved oyster liquor.

Spoon breadcrumb mixture over oysters; drizzle with butter mixture. Broil 5 to 6 minutes or until top is crisp and browned.