Let’s bake up some childhood joy with this Fruity Pebble Cake! First, prepare the oven and pans. Preheat the oven to 350°F (180°C). Line the bottoms of three 6-inch round cake pans with parchment paper circles and grease the sides well. Set aside.

Infuse the buttermilk for the cake batter. In a small bowl, combine the 1 cup + 1 tbsp room temperature buttermilk and the 1/2 cup Fruity Pebbles cereal. Stir them together and set aside while you prepare the other ingredients (letting it steep for 15-20 minutes allows more flavor infusion). Note: Recipe doesn’t say to strain; leaving cereal in adds specks but may affect texture slightly. Straining after steeping is optional.

Prepare the dry and wet ingredients for the cake. In a medium bowl, whisk together the all-purpose flour, baking powder, and kosher salt. Set aside. In the large bowl of your stand mixer fitted with the paddle attachment (or using a large bowl and handheld mixer), cream together the room temperature butter, canola oil, and granulated sugar on medium speed for about 3 minutes until light and fluffy. Scrape down the bowl.

In a small bowl, whisk together the room temperature eggs, vanilla extract, and lemon extract. With the mixer on low speed, slowly stream the egg mixture into the creamed butter/sugar/oil mixture. Mix until well combined, scraping down the bowl as needed.

Now, alternate adding the dry ingredients and the Fruity Pebble-buttermilk mixture (including the cereal bits, unless you strained them) to the main mixing bowl, beginning and ending with the dry ingredients. Add about one-third of the dry ingredients and mix on low speed until almost combined. Add about half of the buttermilk mixture and mix on low until just combined. Repeat with another third of dry, the remaining half of buttermilk, and finish with the last third of dry ingredients. Mix only until just combined after the final addition – do not overmix.

Divide the finished batter evenly among the three prepared 6-inch cake pans (the recipe notes about 370g per pan if weighing). Use a small offset spatula to smooth the tops gently. Bake for approximately 26 minutes, or until the tops bounce back when lightly touched and a wooden skewer inserted into the center comes out clean.

Let the cakes cool in their pans on wire cooling racks for about 20 minutes. Then, carefully run a thin knife or offset spatula around the edges to loosen them and remove the layers from the pans. Let them cool completely on the wire racks before frosting.

While the cakes cool, make the Cereal Milk for the soak and frosting. In a small bowl, combine the 4 tbsp milk and 1/4 cup Fruity Pebbles cereal. Stir and set aside to steep (again, recipe doesn’t specify steeping time or straining; let sit at least 15-20 mins. Straining through a fine sieve after steeping is recommended for smooth frosting/soak).

Make the Cereal Cake Crumb. Preheat oven to 300°F (150°C). Line a baking tray with parchment paper. In a medium bowl, combine the melted butter, flour, granulated sugar, Fruity Pebbles cereal, vanilla extract, and baking powder. Stir together with a spoon or fork until the mixture forms coarse, round crumbs. Spread the crumbs evenly onto the prepared baking tray. Bake for 15 minutes until lightly golden and crisp. Let cool completely on the tray, then break up any large clumps if needed. Set aside.

Prepare the Cereal Milk Buttercream. In a large bowl (or stand mixer bowl with paddle), beat the room temperature butter on medium speed until completely smooth, creamy, and lump-free (about 2-3 minutes). Turn the speed to low and gradually add the sifted powdered sugar, mixing until combined. Increase the speed to high and beat for 2-3 minutes until the buttercream is very light and fluffy. Add 2 tablespoons of the prepared Cereal Milk (strained recommended for smooth frosting) and mix on low or medium speed until fully combined. Note: This makes a small amount for a thin frosting layer; double if desired.

Assemble the Fruity Pebble Cake! Level the tops of the completely cooled cake layers with a serrated knife to create flat surfaces. Place the first cake layer onto your serving plate or cake stand. Using a pastry brush, lightly brush the top of the layer with some of the prepared Cereal Milk soak (use about 1/3 of the milk).

Spread an even layer of the Cereal Milk Buttercream over the soaked cake layer (use about 1/3 of the frosting). Sprinkle about 1/4 cup (or about 1/3) of the cooled Cereal Cake Crumb mixture evenly over the frosting. Carefully place the second cake layer on top. Repeat the process: brush with cereal milk soak, spread with buttercream, sprinkle with cake crumb.

Place the third and final cake layer on top, ideally upside down for a perfectly flat top surface. Brush this layer with the remaining cereal milk soak. Use the rest of the Cereal Milk Buttercream to apply a thin layer of frosting all over the outside (top and sides) of the cake, creating a semi-naked or lightly frosted look. Smooth it as desired with your offset spatula.

Finally, take the remaining Cereal Cake Crumb mixture and press it gently onto the top surface of the cake, concentrating it in the center or creating a border around the edge as desired for decoration. Chill the cake briefly before slicing and serving. Enjoy the Fruity Pebble fun!