Bake the cake:

1. Combine the flour, baking powder, baking soda, and salt in a bowl. In a separate bowl, combine the buttermilk, strawberry jam and vanilla extract.
2. In a large bowl, whip the butter and sugar together with an electric mixer until pale and fluffy.
3. Add the eggs and egg whites one at a time, mixing after each addition.
4. Add the flour mixture to the egg mixture in 3 additions, alternating with the buttermilk mixture.
5. Add the pink food coloring and mix until just combined.
6. Pour the batter into a greased, square 9′ cake pan and bake at 350F for 45 minutes to 1 hour, or until fully cooked. Cool completely.

Make the buttercream:

1. Cream the butter with an electric mixer until pale and fluffy.
2. Add the vanilla extract and mix to combine.
3. Add the confectioner’s sugar one cup at a time, then beat for 3 minutes until fluffy.
4. Add some pink food coloring and mix to combine.

To assemble:

1. Slice the cake into 2 circles, then slice each circle in half to create a total of 4 layers.
2. Spread some buttercream between each layer, then coat the entire surface of the cake with a thin layer of buttercream.
3. Place in the fridge for 15 minutes for the buttercream to stiffen.
4. Coat the cake in a thicker layer of buttercream.
5. Stick Pocky Strawberry sticks around the outside of the cake and tie a ribbon around the cake to secure them.
6. Top the cake with fresh strawberries and enjoy!