Preheat oven to 350°F.* Grease and flour a 12-cup fluted tube pan or 10 x 4-inch tube pan.
Combine cake mix, corn starch, sugar and brown sugar in a large mixing bowl. Add eggs, water, oil, bourbon and vanilla; beat at low speed of electric mixer until smooth. Increase speed to medium; beat 2 to 3 minutes. Stir in 1/2 cup each coconut and pecans. (Reserve remaining coconut and pecans for glaze.) Pour into prepared pan.
Bake 50 to 55 minutes or until toothpick inserted in center comes out clean. Cool in pan 20 minutes. Remove; place on wire rack. While cake is still warm, prepare glaze.
For Glaze: Melt butter in a small saucepan over medium heat. Stir in brown sugar and corn syrup. Cook over medium heat, stirring frequently until sugar dissolves and mixture boils. Remove from heat; stir in bourbon, orange juice and vanilla, if desired.
Pierce warm cake thoroughly with a fork. Brush with glaze. Let stand 30 minutes. Repeat piercing and brushing with glaze. Stir reserved coconut and pecans into remaining glaze; spoon over top of cake.