Preheat oven to 350ºF and line a quarter sheet pan with parchment paper (see notes).

Sift coconut flour into medium bowl. If you can't sift, make sure no lumps are present. Whisk in tapioca flour, baking soda, baking powder and salt. Set aside.

Using electric hand mixer or stand mixer with fitted paddle attachment, combine honey and banana puree or applesauce on medium speed until smooth. Add nut/seed butter mixing on medium-high speed until combined. Add vanilla extract then eggs two at a time, mixing on low-medium speed until combined.

Pour dry ingredients into bowl of wet ingredients and combine on low-medium speed. With mixer running on low speed, carefully add milk and mix until batter is smooth – careful not to over-mix; if lumps are present try breaking with fork. Immediately pour batter into prepared sheet pan, spreading smooth with spatula.

Bake cake for 20-30 minutes, until inserted toothpick in center comes out clean. Watch baking time at 20 minutes as oven temps can vary. Allow cake to cool completely before frosting – about 1 hour.

Meanwhile, prepare frosting and slice strawberries into about 1/4" slices. Make sure they're dry so they don't slide around on frosting. 

Decorate cake: once cake has cooled completely, spread frosting onto cake in even layer. To make flag start in upper lefthand corner of pan and create rectangle with blueberries, about 5x6". Next start at top of pan, next to blueberries, and layer thinly sliced strawberries along top of pan. Continue making strips with strawberry slices until you've created the flag. The number of rows you get will depend on how large your strawberries are. 

Cake can sit at room temperature depending on frosting used, but best to keep chilled until ready to serve. Cut into square pieces and enjoy this festive flag cake.