Start by preparing the ingredients. Cut the butter into small pieces and place them into a small bowl. Melt the butter in the microwave for 30 seconds, then repeat the process for another 30 seconds.

This will make sure that the butter melts evenly without overheating. Set the melted butter aside and let it cool.

Rinse the strawberries and dice them into small pieces.

Peel the bananas and place them into a separate bowl. Use a hand mixer to beat the bananas until they are smooth and creamy.

Sift 4 cups of flour into a bowl. Make sure to reserve ¼ cup of flour to coat the strawberries later. Add salt, baking powder, and baking soda to the sifted flour. Mix all the dry ingredients together until they are well combined. Set the flour mixture aside until you are ready to use it.

Preheat your oven to 350°F. In a large mixing bowl, beat the eggs and sugar together on high speed for 5 minutes. This will help to incorporate air into the mixture, resulting in a lighter and fluffier cake.

Reduce the speed of your mixer to low and slowly pour in the melted butter. Add vanilla extract and the mashed bananas to the mixture. Increase the mixer speed to medium and beat for an additional 30 seconds. This will guarantee that all of the ingredients are well incorporated.

Reduce the stand mixer speed back to low and gradually add the flour mixture, one cup at a time. Mix well after each addition to make sure that the flour is fully incorporated into the batter.

Take the reserved ¼ cup of flour and coat the diced strawberries. This will help to prevent them from sinking to the bottom of the cake during baking. Gently fold the flour-coated strawberries into the batter using a spatula. Be careful not to overmix, as this can result in a dense cake.

Line two 9x12 baking pans with parchment paper. Pour the batter evenly into the pans, spreading it out with a spatula to guarantee an even bake.

Place both pans into the preheated oven and bake at 350°F for approximately 45 minutes, or until the cakes are golden brown. To check for doneness, insert a toothpick into the center of the cake. If it comes out clean, the cakes are ready to be removed from the oven.

Remove the cakes from the oven and let them cool in the pans for 5 minutes. This will help them to set and firm up before removing them from the pans. After 5 minutes, carefully remove the cakes from the pans and transfer them to a cooling rack. Allow the cakes to cool for an additional 15 minutes before slicing.

Dust each cake with powdered sugar. This will add a touch of sweetness and create an attractive appearance.

Cut each cake into equal 15 pieces. For a prettier presentation, you can place each piece of cake onto cupcake liners.

Arrange the cakes on a platter and enjoy! Serve them as a delightful treat for any occasion.