Preheat your oven to 350°F (175°C) and grease a 13 x 9 inch baking dish.

Combine the strawberry cake mix, guava juice, eggs, and melted coconut oil in a mixing bowl and mix on low for about 30 seconds. Then mix on medium-high for 2 minutes.

Pour the batter into the prepared baking dish and spread it evenly. Bake for 24–26 minutes until a toothpick comes out clean.

Let the cake cool in the dish for about 10 minutes, then transfer to a wire rack to cool completely.

Beat the cream cheese until fluffy, then mix in sugar and vanilla. Fold in the Cool Whip and refrigerate until the cake is cool.

Combine guava juice and sugar in a saucepan, bring to a simmer. Whisk cornstarch with water to make a slurry, then whisk into the simmering mixture until thickened. Cool completely.

Spread the cream cheese layer over the cooled cake and drizzle the guava gel on top.

Cover the cake with plastic wrap and refrigerate for at least 2 hours. If desired, sprinkle with coconut flakes before serving.