Looking for the perfect bundt cake? Try this Strawberry Swirl Bundt Cake - a moist vanilla cake with a strawberry swirl inside, topped with fresh berries and beautiful buttercream flowers! This recipe calls for 2-3 cups of prepared buttercream frosting. You won’t use all of this, but if you want an assortment of colors, you’ll need enough frosting to provide that variety, and will have some left over for another use. You can use any fairly stiff homemade frosting you have on hand—my favorite is this Easiest Swiss Meringue Buttercream recipe.
Preheat the oven to 375 F. Spray a 10-15 cup bundt pan with nonstick baking spray—I like the Bakers variety with flour mixed in.
Combine the sugar, butter, baking powder, and salt in the bowl of a large stand mixer fitted with a paddle attachment. Mix on medium-high speed for about 5 minutes, until very light and creamy.
Turn the mixer to medium-low and add the eggs one at a time, beating well after each addition, then mix in the vanilla extract.
With the mixer running on low, add about a third of the flour. After the streaks have disappeared, add half the sour cream. Continue to alternate the wet and dry ingredients until they are all added to the batter, stopping when just a few streaks of flour remain. Stir the cake batter with a spatula, scraping the bottom and sides of the bowl well.
Separate out about a third of the batter, and add the strawberry puree, chopped strawberries, and pink food coloring (if using) to the batter. Stir gently just to incorporate.
Add half of the plain batter to the bundt pan, then add the strawberry batter on top, and finish with the rest of the plain batter. Twirl a knife or skewer through the batter to swirl the flavors together.
Bake the bundt cake at 375 F for 55-60 minutes, until a toothpick inserted into the center comes out clean. Let the cake cool for 15 minutes, then place a wire rack on top and invert the cake. Carefully remove the cake pan and let it cool completely before decorating.
Whisk together the powdered sugar, milk, and lemon extract until smooth and shiny. The glaze should be fairly thick, so that it looks opaque on the cake, but thin enough so that it drips down and doesn’t just sit in a clump on top. I like to aim for the thickness of a pancake batter to start. If it seems too thick, add a bit of milk, and if it seems to thin, whisk in a little more powdered sugar.
Spoon the glaze on top of the cake, and use the spoon to nudge it down between the ridges of the bundt cake. Let the glaze set for at least an hour before finishing the decorations.
Fit a piping bag with a #2 tip and fill it with green frosting. Pipe a swirl of vines over the top of the cake.
Pull the stems off the strawberries, and cut them in half. Press the half strawberries, cut side down, in even intervals around the top of the cake. Use the green buttercream to draw frosting stems on each strawberry.
To make multi-colored flowers, lay out a piece of plastic wrap about 12 inches long. Spread a rectangle of frosting on the center of the plastic wrap. Take a second color of frosting and spread it on top of the first. If desired, add a third or even a fourth color on top. Roll the frosting over itself to make a cylinder. Grasp the ends of the plastic wrap in each hand, and twirl it quickly so the frosting is burrito-shaped and the ends of the plastic are tightly twisted.
Fit a large piping bag with one of your Russian piping tips. Snip off one of the plastic wrap “tails” and insert the frosting cylinder into the piping bag, snipped-side down. Hold the piping bag perpendicular to the top of the cake, about ½-inch from the top. Squeeze with steady pressure until the frosting comes out and forms a flower shape. Stop squeezing, then lift the tip so that the frosting tapers off into flower petals.
Add flowers of various colors and shapes all around the top of the cake—you can make it as sparse or as full as you want. Finish by swapping the tip on the green piping bag for a leaf tip, and add green leaves in between the berries and flowers.