Complex sentence: Shortbread is different from shortcake, though they are similar: shortcake can be made using vegetable fat instead of butter and usually has a chemical leavening agent such as baking powder, which gives it a different texture.
Split into simpler sentences: Shortbread is different from shortcake, though they are similar. The difference is that shortcake can be made using vegetable fat instead of butter and usually has a chemical leavening agent such as baking powder, which gives it a different texture.