Best Peach Cake with Brown Sugar Frosting

Bahan-bahan (12 porsi)

• 1 (15-oz) box yellow cake mix
• 2 (3-oz) boxes Peach Jell-O (not made)
• 4 eggs
• 1 cup oil*
• 1 (16-oz) bag frozen peaches (do not thaw**)
• 1/2 cup salted butter ((1 stick))
• 2 cups brown sugar (packed)
• 2/3 cup heavy cream
• 1 teaspoon vanilla
• ice water (for an ice bath, not to go in the recipe)