Sieve the dry ingredients to avoid lumps
Mix dry ingredients together in one bowl and mix wet ingredients in another bowl. Then add one bowl to another and mix well.

For the buttercream, add the butter to a mixing bowl or the bowl of a stand mixer and beat for 5 minutes until light, pale and doubled in volume.Gradually add the sugar ½ cup at a time beating well in between each addition.Once all of the sugar has been incorporated add the vanilla and milk (if you choose to add the milk)

I used Russian tips for piping the flowers. Watch this video for guidance: https://youtu.be/TRAgXne621o