Preheat oven to 350 degrees F. Lightly coat a 9x9x2-inch baking pan with nonstick cooking spray; set aside.
In small saucepan combine brown sugar, 2 Tbsp. butter, and water. Cook and stir over medium heat until mixture comes to boiling and is smooth. Pour in prepared pan; tilt to evenly coat bottom. Arrange pineapple slices over top.
In medium bowl combine flour, baking powder, salt, and nutmeg; set aside.
In large mixing bowl beat 1/2 cup butter on medium-high 30 seconds. Gradually add granulated sugar, beat until combined; beat 2 minutes more. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Alternately add flour mixture and 3/4 cup milk; beat on low after each just until combined. Stir in carrots. Spread batter over pineapple.
Bake 45 minutes or until golden and wooden pick inserted in center comes out clean. Cool in pan on rack 5 minutes. Invert on platter. Cool 30 minutes. Makes 9 servings.