How'd she do it?

I know. I know. It's OK. I know you've spent the whole weekend thinking, "When will Flour Girl tell us how she made that amazing cake that looks exactly like a peanut-butter-and-jelly sandwich?" "Why must she torture us like this?"

I'm sorry to leave you in suspense, my cake-eating friends. But no more.

Now you, too, can go forth and create your very own Peanut-Butter-and-Jelly Sandwich Cake.

First, as with all good things in life, you must start with cake. I wanted one that would look like sandwich bread, so I first considered white cakes. But I also wanted it to be moist and firm and not-too-fluffy, so it wouldn't crumble. So I settled on a super-tasty and easy Yellow Butter Cake from Joy of Baking. Perfect color and texture; this cake's a keeper -- even for uses other than creating crazy sandwich cakes.

I made two 8X8-inch layers, but they came out a tad thick for bread. So, I just sliced each one in half before filling. Hey, what's better than one cake? Two cakes!

Then, of course, I needed the filling. Since I love all things that come out of the Smitten Kitchen, I figured I couldn't go wrong with Deb's Peanut Butter Frosting. Another keeper. I mixed in some white chocolate chunks to make it seem like chunky PB.

For the J layer, I simply stirred a jar of mixed-berry jelly to make it easier to spread.

I wanted to see a little peanut butter peeking out from the "bread." So I spread it on thick and left it a little messy around the edges.

I frosted the top of the cake with Marshmallow Creme Frosting (love the Jet-Puffed Marshmallow Creme!) And, here's one time when you don't have to worry about a few crumbs mixing in your frosting. Makes it look more like real bread.

I added a teaspoon of cocoa powder to about a third of the Marshmallow Creme Frosting and spread that around the cake's edge for the "crust." A Twitter friend later suggested patting crushed graham crackers around the edge for a more-realistic look -- a great idea, I think.

Congratulations! Now you've got a giant Peanut-Butter-and-Jelly Sandwich Cake. Use a nice, big serrated knife to cut it in quarters, serve with a giant glass of milk and be sure to share with a friend or 16.