do you charge your clients delivery fees for delivering the cake/cupcakes to their event?
Yep, we charge $1/minute for travel time (round trip) and setup time.
Weddings, no (locally) - parties, yes: $20 in town and $3/mile (calculated one way... or $1.50 both ways if you like) out of town.
Mine is mainly a delivery business. I deliberately priced my local delivery just below florists and Edible Arrangements.
For delivery, you really have to develop a pricing structure that is relevant to your area, the clients you serve, the type of cakes you make.
I have a minimum order, a delivery fee, and another minimum order threshold to receive free delivery. If I agree to do a cake under my minimum order amount, there is a supply fee AND a delivery fee. If they don't want to pay the delivery fee, we arrange for the client to pick up their order and sign that they received the cake in good condition, etc.
You might need to do some research on your competitors.
$1.50 per mile (one way), so $0.75 per mile round trip.