Place margarine in 1-quart casserole.
Microwave uncovered on high (100%) until melted, 20 to 30 seconds.
Stir in brown sugar, pecans, corn syrup and cinnamon; spread evenly in casserole.
Microwave uncovered until bubbly, 45 to 60 seconds.
Tilt casserole so brown sugar mixture runs to side; place 6-ounce juice glass in center of casserole.
Mix baking mix and water until soft dough forms.
Drop dough by 6 spoonfuls onto brown sugar mixture.
Place casserole on inverted plate in microwave oven.
Microwave uncovered on medium-high (70%) 2 minutes; rotate casserole 1/2 turn.
Microwave uncovered until wooden pick inserted in center comes out clean, 2 to 2 1/2 minutes longer.
Immediately invert on heatproof serving plate; let casserole stand 1 minute so caramel can drizzle over coffee cake.