Peanut Butter Cake with Homemade Grape Jelly

Baby Cake #9: Peanut Butter Cake with Peanut Butter Buttercream and Homemade Grape Jelly

peanut  Butter Cake with homemade grape jelly

Full disclosure: we never got to actually taste a slice of this double-decker PBJ-inspired baby cake for month #9 because I finally let Lucy James go for it. She has two teeth on the bottom and two more coming through on top, and the poor girl deserved to have her cake this time, instead of being teased by mommy again.

I let her paw it like a bear cub, and she knocked it on the floor, straightaway.

Homemade Cabernet Jelly for PBJ Cake

Despite that, we tasted all the components: peanut butter buttercream, tart-sweet Cabernet grape jelly and fluffy peanut butter cake, and I feel quite certain that any baby (or adult) would be thrilled to have this PB&J inspired cake on their birthday.

Homemade Cabernet Grape Jelly

I halved a recipe I found from the New York Times by actress and fellow Tennessean, Ashley Judd, to fit my little 4” baby cake pans, and I tweaked it a bit, using yogurt in lieu of buttermilk. I made Cabernet jelly from scratch because I live here in Sonoma and have always wanted to try it.

I’m sharing that recipe, too, but there’s no shame in grabbing a jar of Concord grape from the store for this one. Concord grapes have a beautiful floral note and higher acidity than my Cabernet grapes, lending themselves to a more evenly balanced, less sweet jelly, not to mention widely available year-round;)



recipe adapted from New York Times by Ashley Judd


  • 4 oz unsalted butter, softened

  • 3/4 C sugar

  • 3/4 C cake flour, sifted

  • 1 egg, separated

  • 1/8 cup creamy unsalted peanut butter

  • 1/2 tsp baking powder

  • 1/4 C plain yogurt

  • 1/2 C water

  • 1/2 tsp baking soda

  • 1/2 tsp salt


  1. Preheat oven to 375 degrees.

  2. Grease and flour four 4” square cake pans.

  3. In a standing mixer using whisk attachment, beat softened butter with sugar. Add yolks, then peanut butter and whisk until smooth.

  4. In a separate bowl, combine flour and baking powder and set aside.

  5. In another bowl, combine the yogurt and water and whisk until smooth, and then add baking soda.

  6. With mixer running on low speed, add the flour mixture and yogurt mixture to the peanut butter-yolk emulsion, alternating, beginning and ending with flour mixture.

  7. Next, in a clean bowl, using a hand mixer, beat the egg whites until stiff. Fold into the cake batter with a rubber spatula until smooth and combined.

  8. Spread the batter into prepared pans and bake 25-30 minutes, until a wooden pick inserted into the center comes out clean.

  9. Let cakes cool completely in pan until you’re ready to assemble layers.


Cabernet Grape juice

Rather than canning my jelly for preserving, I made an instant jelly for immediate use in this cake. If you’d like to increase the quantity and can your jelly for future enjoyment, be sure to follow safe canning procedures for sanitizing and sealing your jars here.


  • 3 bunches Cabernet grapes or about 2 cups, stemmed grapes

  • 1/2 C sugar

  • 1/2 tsp pectin

  • juice of half a lemon


  1. Wash stemmed grapes and add to blender to “crush” and liquify.

  2. Pour liquified grape juice through a fine mesh sieve to remove seeds and skins, leaving ~1 cup fresh juice.

  3. Pour juice into a medium sized heavy sauce pan and heat over low heat until bubbling

  4. Add sugar, lemon juice and pectin and stir continuously until juice thickens and coats the back of a spoon.

  5. Pour jelly into a clean 8 oz jar, seal and let sit until cool, then store in refrigerator for several hours until set. Once set, use immediately or within 3 days.

Peanut Butter Buttercream


  • 5 egg whites

  • 1 cup sugar

  • 1 lb unsalted butter, softened at room temperature

  • 1/2 C unsalted creamy organic peanut butter


  1. In a double boiler, combine egg whites and sugar over medium heat until sugar is completely dissolved.

  2. Pour egg white syrup through a fine mesh sieve, to remove any bits of cooked egg white, and pour syrup into the bowl of a standing mixer with whisk attachment.

  3. Whisk syrup on high speed for several minutes until you have a thick glossy meringue, and then add butter, one stick at a time, while whisk is running until butter and meringue are completely emulsified. Don’t fret if buttercream looks like cottage cheese at the beginning; keep whisking, and it will come together.

  4. Finally, add peanut butter and whisk thoroughly.

  5. Switch whisk to a paddle blade and beat peanut buttercream for one minute to remove air bubbles before prepping cake.


  1. Once cakes have cooled. Level tops to create four 3/4”-1” tall layers. You’ll have some left over tops for snacking:)

  2. Next, pipe a dab of buttercream on a 6” cake board to hold cake in place, then top with your first layer.

  3. Pipe a thin layer of buttercream over square cake to cover completely, then smooth with an offset spatula, pushing edges of buttercream up towards edge of cake to give appearance of PBJ oozing out through edges.

  4. Next top buttercream with a heaping tablespoon of jelly and push toward the edges on top of buttercream to continue the sandwich look, being sure to leave a few edges of buttercream without jelly to keep cake from slipping. (The buttercream acts like glue when chilled, holding cake together, so be sure it isn’t 100% covered in jelly.)

  5. Repeat steps 4 and 5 with remaining cake layers, with the exception of the top layer, which you’ll frost with just buttercream.

  6. Style with fresh grapes on the vine and dig in!

Peanut Butter and Jelly Bake Cake Idea
Homemade PBJ Smash Cake Idea for Baby
Smashed cake, recovered from the floor:(

Smashed cake, recovered from the floor:(

Find tools and supplies i used in this recipe (like the 4” cake pans and cake leveler), over here:)

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