Step 1

Pre-heat oven to 350°F an grease and line a 9 inch round cake pan with parchment paper. Whisk together flour, baking powder, cardamom, and salt together and set aside. In a bowl of a stand mixer, add sugar and orange zest. Use your finger to rub the zest into the sugar until the sugar is pale orange. This helps extract the oils and flavor from the zest. Add butter and mix with a paddle attachment for 7 minutes, scraping the bowl down every few minutes. The butter should be light and fluffy. Scrape down the bowl and add the egg (or egg replacement), vanilla extract, and cardamom extract. Mix for 3 minutes until well combined and fluffy. Add the flour mixture and milk in 3 alternating additions, mixing well in between each addition. After the final addition, mix until just combined. Use a spatula to gently fold the batter to make sure everything is mixed in and smooth. Pour the batter in and smooth into an even layer. Tap the pan on the counter 2-3 times to get rid of any air bubbles. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. Cool completely.

Step 2

Add egg whites (or aquafaba), sugar, cream of tartar and salt into the bowl of a stand mixer. Set up a double boiler and place the bowl over a pot of simmering water, making sure the bottom of the bowl doesn't touch the water. Stir for 5 minutes or until the mixture hits 160°F. Then remove from the heat. Attach the bowl to the mixer and whisk for 12 minutes or until the bowl is body temperature (90F). Add butter a tablespoon at a time, mixing well in between each addition. Add powdered sugar and cardamom extract. Whisk well. If it's soupy or loose- pop the bowl in the fridge for 15 minutes and then continue whisking. It should be creamy, smooth and light.

Step 3

Set aside 1 cup of frosting. Spoon the rest of the buttercream into a piping bag or sandwich bag and cut off a 1/2 inch corner. Pipe a circle around the edge of the cake. Fill the cake with orange marmalade and spread into an even layer. Pipe additional buttercream on top and smooth into an even layer. Pop the cake into the fridge to set. Split the buttercream into 5 bowls by placing 2 tbsp each for the purple and red frosting and 1/4 cup each for pale orange, orange and pink (dusty rose) frosting. Mix it in until you get the colors you want. Swipe the purple, orange, and red buttercream onto the cake. Then take the pale orange and pink frosting and plop down a thick bit small layer. Use your offset spatula to then swipe lines into the buttercream to create some texture. Spoon the rest of the pink, orange and pale orange buttercream into a piping bag fitted with a star tip and pipe random dots onto the cake. Add sprinkles and candied orange slices to decorate. Store in the fridge and remove from the fridge for at least 3 hours before serving.