Kiddo's love it and adults are REALLY surprised!! All the flavors you've loved your whole life! I created this cake for my kids and now their kids love it too. Great "carry" cake or fun Birthday cake for the PB&J lover.
In large mixing bowl, blend eggs, oil, water and cake mix until blended. Beat on medium speed with mixer about 2 minutes. Pour into pan and bake until done about 25-30 minutes.
While cake is baking: boil 1 cup water, remove from heat and stir in Jello until dissolved. Add grape jelly and stir til jelly melted and dissolved.
When cake tests done, remove from oven. While hot, poke holes throughout top of cake (I use handle of wooden spoon). Pour grape Jello mixture all over top of hot cake letting mix into all holes. Set aside to cool on rack.
In large mixing bowl, combine softened butter, peanut butter, vanilla and salt. With mixer at medium speed, mix about 2 minutes til well blended and somewhat fluffy. Add confectioners sugar 1 cup at a time(stop the mixer to add!) Beat on medium til all sugar is incorporated and consistency is thick frosting. Spread on cooled cake covering entire top with thick layer of frosting. As a finishing touch, I add a TINY sprinkling of salt to top of frosting or crushed salted peanuts.