Step 1
Preheat an oven to 325 degrees F (165 degrees C).
Step 2
Cut a 12x14-inch sheet of aluminum foil. Fold it in half lengthwise then in half again widthwise.
Step 3
Wrap the foil partially around a spice jar lengthwise bringing foil up around the jar and crushing the foil around the ends of the jar to make a boat-shaped baking form about 4 inches long 2 1/2 inches tall and 1 1/2 inch wide. Repeat with 15 more pieces of foil to make 16 boat-shaped baking forms. Shape the bottoms of the forms to be slightly flat so forms can stand up.
Step 4
Spray the forms with cooking spray and place onto a baking sheet.
Step 5
Mix together 1 cup water eggs and vegetable oil in a bowl with an electric mixer set on low speed.
Step 6
Beat in yellow cake mix on medium speed for 2 minutes.
Step 7
Beat in the vanilla pudding mix until smooth about 3 minutes more.
Step 8
Divide the batter evenly into the prepared aluminum foil baking forms filling each form about 1/2 full.
Step 9
Bake in the preheated oven until a toothpick inserted into the center comes out clean 11 to 15 minutes. Cool in the forms for 10 minutes before removing to cool completely on a wire rack.
Step 9
Beat together the butter shortening vanilla extract and salt in a bowl with an electric mixer until smooth about 3 minutes.