Preheat oven to 350 (175 celsius). Cream together 1 cup of sugar and ½ cup unsalted butter. Add in two eggs, and mix in vanilla. In a separate bowl, combine 1 ½ cups all-purpose flour and 1 ¾ teaspoons baking powder. Add the wet ingredients to dry ingredients and mix well. Add milk and stir until the cake batter is smooth.

Separate one-third of the cake batter out and color it green. Add pink food coloring to the rest of the batter. The green cake will be the bottom slice of this watermelon themed cake.

Pour the batter into three greased cake pans. One cake pan will be for green cake, and two cake pans for pink cake. Bake for 20-30 minutes until the cake springs back when lightly touched. Cool cake completely then wrap it in plastic wrap and freeze it.

Make sure you trim the top of the cakes so they are flat and level. Trim the outer ring of the cakes so the size of each cake layer is the same (so it’s not lop-sided). Trimming the border of the watermelon cake also gives it a nice look if you’re not going to cover it up with frosting. The exposed cake is a brighter color and looks cleaner when it’s been trimmed.

Make your vanilla buttercream frosting with 1 cup of butter and about 4 cups of icing, 1 tsp of vanilla and 2 tsp of cream or milk. Blend it with a hand mixer or stand mixer until it’s fully mixed and no sugar crystals remain. If you think you've put in too much moisture with your milk or cream, try adding a bit more powdered sugar or put your icing in the fridge to firm up if it's starting to melt.

Take a big spoonful of your icing out into a new bowl and mix in black food coloring. Set aside this black icing for later, you'll use it as your 'watermelon seeds'. The rest of your frosting you can color a light pink shade.

Use your favorite piping tip (I used a large star tip) and fill a piping bag with light pink frosting. Put a layer of thick frosting between each cake layer. Then pipe stars or swirls on top of your watermelon smash cake.

Decorate your 1st birthday watermelon smash cake to make it look like there are ‘seeds’ on top of the cake that are still safe for your baby to eat. Do not use anything that could be a choking hazard for your birthday boy or girl.

Dots of black icing are one of the safest options for the watermelon seed decorations. Use a ziploc bag or piping bag and cut a very small hole in the tip or corner of the bag. Add your black icing and as you squeeze out a small amount, use a toothpick to cut the icing stream and apply it to your cake, as seen in my photos.

Wipe off your toothpick between applying each ‘seed’ so your cake doesn’t get messy with black icing in spots you don’t want it.