Frozen, packaged pound cake works well here; the dense texture cuts evenly and doesn't crumble. Use homemade or deli pound cake if desired, but steer clear of varieties with nuts and chocolate chips, which make skewering tricky.
Soak skewers in water 30 minutes. Preheat grill to medium-high heat (350° to 400°).
Heat butter and brown sugar in a small saucepan over medium heat, stirring until well blended. Stir in whipping cream and bourbon. Remove from heat; set aside.
Thread berries and pound cake evenly onto skewers. Place on well-greased grill grates, and grill 1 minute on each side or until cake is lightly toasted. Serve with bourbon-butterscotch sauce.