Sonic Birthday Cake

It’s about a month from my son’s birthday and we’re hanging out in the living room. It occurred to me that it was close to his birthday and I should probably start finding a bakery to order his cake, find out the theme etc. I asked him what kind of cake he was thinking about and he says “oh! I’ll show you”. He was flipping through sonic pics on the ipad and shows me something that looks like this:

My actual cake, not the one my son found.

I’m like “Are you serious?!? That’s a $300 cake easy!”, his reply, “are you up for the challenge?” I haven’t touched fondant since 2005 and I’ve never made a tiered cake like this, but at the same time I felt my self-imposed competitive streak chime in and I agreed to do the cake. He then tells me “and don’t worry about making the Sonic figure, you can use mine.” “Oh. Ok. Thanks.” I made it very clear that he shouldn’t have very high expectations, and he had to promise to not be embarrassed in front of his friends if the cake was a disaster. I immediately went into a fit of self-confidence and states of panic at the same time. How in the hell was I going to pull this off? I called a close girl friend from school that now works for a cake design bake shop and asked for advice. She reminded me of dowels and boards and the types of cake needed to support the different tiers,  how much fondant I would need and timelines for getting it all done. I then called my mom and we compared our recipes and tested out a few. Thankfully, he only wanted a yellow cake with vanilla frosting.

About two weeks out, I started baking the cakes and put them in the freezer. In the evenings after work, I would dye the fondant and cut out the rings.


I did the actual assembly of the cake in one day. It seemed to take forever, by the end I really started to not care and wanted it to be done. It was worth it in the very end, because my guy was thrilled. Oh, and I had to invite every person I knew in town to eat this cake. He only had 3 guys sleeping over to eat a cake that easily fed 90 people. I was able to take an entire tier to the office to share with my coworkers.


A note about the cake: The recipe I’m posting is very special. In sentiment and application. The recipe came from a friend of Edith’s (my grandmother), and she had no idea where it came from. Her name was Ruth, so we call it “Ruth Cake”. It is the most dense, moist, and temperamental pound cake I’ve ever had/made. You have to start in a cold oven and you have to be very careful not to over beat or shake the pan too much. I decided to be a pioneer and try to make this cake in layer pans. It didn’t turn out too badly. Luckily, I had to cut the tops of the layers off anyway to even them out.

Also! The recipe calls for margarine. We tried butter once and it fell. We’re not really margarine people, but we make an exception for this recipe.


A note about the buttercream: For whatever reason I decided to make a traditional swiss buttercream. I thought “I haven’t done something like this in a very long time, so why not?” This recipe is good, but it has an insane amount of butter in it. I only used about ¾ of what it called for. It was delicious, but you will definitely have to cut back on the fats for a while after eating it.


Ruth Cake

  • Servings: one 10 inch bundt cake
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All ingredients should be at room temperature. DO NOT PREHEAT OVEN!

  • 3 cups sugar
  • 1 pound Imperial margarine
  • 1 8oz pkg cream cheese
  • 6 eggs
  • 3 cups sifted cake flour
  • 3 tsp vanilla

Tube pan


Butter and flour the tube pan.

Cream together margarine, cheese and sugar until fluffy. Alternated adding the flour with the eggs. Start with one cup of flour, 2 eggs, ½ cup flour, 2 eggs, ½ cup of flour, 2eggs plus vanilla, then remaining 1 cup of flour. Once all of the ingredients have been incorporated, beat on medium speed for about 30 seconds.

Spoon batter into the pan and place the pan into a cold oven. Bake at 350°F for approximately 90 minutes or until a cake tester comes out clean.

Swiss Meringue Buttercream


  • 12 oz egg whites (10 large egg whites or about 1 1/2 cups)
  • 3 cups granulated sugar
  • 3 lbs unsalted butter, room temperature
  • 2 Tbsp lemon extract, almond extract, orange extract, or pure vanilla extract

Lightly whisk egg whites and sugar together over simmering water until egg-white mixture is hot to touch or a candy thermometer reads 140°F (60°C). Pour hot whites into a room-temperature bowl and whip with a wire whip until double in volume on MEDIUM-HIGH speed.

When the mixer stops, the meringue should not move around in the bowl. Meanwhile cut up butter into 2-inch pieces. (The butter should be slightly moist on the outside but cold inside.)

On your mixer, remove the whip and attach the paddle. Add half the butter (1 1/2 lbs) into the bowl immediately and pulsate the mixer several times until the meringue has covered the butter completely. To pulsate the mixer, turn it on and off in a jerky motion. This forces the butter on the top to the bottom of the bowl. Add the balance of the butter (1 1/2 lbs) and pulsate mixer several times. Slowly increase the mixer’s speed, starting with the lowest speed and increase the speed every 10 seconds until you reach a MEDIUM-HIGH speed.

Continue beating until the mixture begins to look light and fluffy. Stop the mixer and scrape the bowl. Reduce speed to LOW. Add flavoring and continue to beat on LOW speed for 45 seconds. Then beat on MEDIUM-HIGH speed for an additional 45 to 60 seconds.

Leftover buttercream can be placed in plastic containers with lids and kept in the freezer for up to 3 months. Defrost completely (several hours) and rewhip before using.