Perfect-For-Picnics Peanut Butter Sheet Cake

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Hi there. It’s been a while, I know. Last week was sheer madness with the end of the school year closing in for my third grader. We had to get through his big school events like the school field day, the annual end-of-the-year field trip and the end-of-school-year dance. We were also the lucky invitees to a couple of fun, end-of-the-year birthday parties for some of our sweet friends. 

Needless to say, we were out and about a whole lot.

We also navigated all of the aforementioned social events while nursing a sick dog back to health and this involved multiple trips to the veterinarian. Two weeks ago, we had lots of excitement at home when my little dog ran out the front door and found himself in a situation that spiraled into some unplanned surgery for my naughty boy. Those of you that know me personally, know all about my spirited (kindest word I can think of at the moment, but what I really mean is mischievous!), sweet, and very loved Jack Russell Terrier, Rex.

For those of you who aren’t familiar with my little dog, or the breed, they are known rascals. When it comes to getting into trouble, Rex is an over-achiever and an uber-rascal of sorts, and we’ll leave it at that. But, anyhoo, he’s on the road to recovery and back to being his crazy, little self.   

Okay…wait. What am I posting about? Oh, yes…CAKE!  

Well, here she is, the first post I’ve managed to put together since the school year ended!  

Oh, buddy, you are gonna love this one… peanut butter sheet cake with peanut butter icing! 

Sound rich? Yes, it kinda sorta is, but not so rich that you should think you can live without it. You can’t. Okay, well you can live without it, but if you are able to you really should try it.

I had a few other recipes in mind for today’s post, but I figured this cake recipe was a super useful one to share today.

It is absolutely perfect for large, summer get-togethers. 

It’s ridiculously delicious and it’s certainly big enough to feed a crowd. 

Really, I mean it. Your kids and your Aunt Sallie are gonna go nuts for this cake! 

And, I guess I’ll go ahead and warn you now to prepare yourself for all the requests for this recipe you will get. 

So, be proactive and print up some cards or something. 

From here on out, it’s really up to you if you want to share, and I really appreciate it if you do. 

But, it’s also perfectly understandable if this becomes your classified, “ace in the hole” recipe for family gatherings this summer and for future seasons too.  

Your secret is safe with me. 
**this recipe has been edited since I originally posted it on 6/8/2016. I realized a previous edit that included pan prep instructions and baking temperature didn’t take, so I wrote it back in! Love, MB

Peanut Butter Sheet Cake                            printable recipe

** you will need an 18×13 inch sheet pan, if you don’t have one. I bought the ones I have at a local restaurant supply store and they have become the pans I use the most in my kitchen! Love them.  You can also conveniently purchase one on Amazon through this link –>

For the cake:

  • 2 cups all-purpose flour
  • 2 cups sugar
  • 1 1/2 teaspoons baking powder
  • 1/2 cup creamy peanut butter (I used Peter Pan brand)
  • 2 sticks (1 cup) salted butter
  • 1 cup hot water
  • 1/2 cup milk (I used 1% milk)
  • 2 large eggs, beaten
  • 1 1/4 teaspoons pure vanilla extract

For the icing:
  • 1 stick (1/2 cup) unsalted butter
  • 1/4 cup creamy peanut butter
  • 1/3 cup plus 2 teaspoons milk
  • 1/2 teaspoon pure vanilla extract
  • 4 – 5 cups powdered sugar, sifted (yes, it’s important you really sift it to prevent lumpy icing!)

1.  Prepare your baking sheet with non-stick cooking spray and a large sheet of parchment paper and set it aside. Preheat the oven to 350ยฐ.

2.Combine the flour, sugar, baking powder in a large mixing bowl. Mix the dry ingredients well and set the bowl aside.

3. In a medium-size sauce pan, combine the butter and peanut butter in a sauce pan and melt over medium heat. Once the butters are melted add the hot water and stir well. Remove from the heat and let it cool down for just a minute or two. 

4. Pour the hot butter mixture over the flour mixture and mix it well with a wooden spoon until the ingredients are just combined. (don’t over mix it, be gentle)

5. Pour in the beaten eggs, milk and vanilla. Mix until the batter is just combined.

6. Pour the batter onto the prepared baking sheet and spread it out as evenly as possible. Bake for 20 minutes or until a toothpick inserted in the center of the cake comes out clean. While the cake is baking, prepare the peanut butter icing.

7. For the icing, combine the butter and peanut butter in a saucepan over medium heat. Add the milk and bring just to a boil and turn off the heat. Add in the vanilla extract. Add the sifted powdered sugar, one cup at a time stirring with a wooden spoon or a whisk. Icing should be a medium-thick, glue-like consistency when ready. Cover the pan (or bowl if you transferred your icing, like I did) with plastic wrap or aluminum foil until it is time to use it otherwise it will start to dry in the bowl.  

8. Once cake is done, set baking sheet on a cooling rack and allow it to cool for 15 minutes. Pour your icing over the warm cake. Spread it out evenly and then allow it to cool completely.

9.  Serve and enjoy!


  1. Peanut butter desserts are some of my favorites! I can imagine this was a huge hit!

  2. Dear Marcelle, what a wonderful recipe and no chocolate in sight – I believe I have to give this recipe a try as my kids are quite infatuated with peanut butter these days!
    Great recipe inspiration, dear friend!
    Wishing you and your family a wonderul week,

  3. Love peanut butter! Cake, cookies, spooned from the jar — I'll take it any way I can get it. But it's best in baked goods, I think. And peanut butter icing? Wonderful stuff. This is a great recipe — thanks so much.

  4. A double dose of peanut butter, now that sounds really good. I grew up in Texas and at almost every social event you would find a sheet cakeโ€ฆsuper easy to cut and serve.

  5. This would be a huge hit at end-of-year parties! Sounds yummy.

  6. this is probably the most desirable sheet cake i've ever seen. LOVE peanut butter glazes!

  7. This time of year is busy for everyone! For me, it's the yard and garden that times up much of my time, not to mention a temporary summer job that I've had for about 8 years kicks in this time of year. What a delicious cake and I'm sure one my grandsons would love too ๐Ÿ™‚

  8. Absolutely scrumptious Marcelle. I really want some now.

  9. Thank you, Liz! And thank you for your visit! I'll look up your other sheet cake recipe, I love these big cakes for parties!

  10. Cheri, the end of school madness was exhausting, but I love it all the same! Thank you ๐Ÿ˜‰

  11. David, I've taken your anticipation as a huge compliment ๐Ÿ™‚ thank you, friend! I promise this cake is good stuff.

  12. We are huge peanut butter fans in our family, and this looks amazing. Thank goodness you made it through the end of the year, my kids are much older now but I remember there was always one thing after another. Lots of fun but exhausting. Take care!

  13. Oh, gosh, this cake looks so moist and fabulous!!! I finally made my first non-chocolate sheet cake and now I think there's another I MUST try!

  14. I am a huge peanut butter fan, in this cake looks amazing. As soon as I saw it on Facebook, I knew I couldn't wait for the recipe to come in my email. By the way, I love Jack Russell terriers. They are so cute but, yes, mischievous!

  15. Peanut butter to go! I love this cake. GREG

  16. Hi there, Angie! It's a great cake! Thank you ๐Ÿ™‚

  17. My husband is crazy for anything peanut butter. This looks so delicious with that shiny peanut butter glaze.

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