In a saucepan, combine guava juice and sugar over medium heat, stirring until the sugar dissolves completely. In a separate bowl, mix cornstarch with water to form a slurry, then add to the saucepan. Bring to a gentle boil, stirring constantly until thickened, about 2-3 minutes. Remove from heat and cool in the refrigerator for about 30 minutes.

Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners. In a large mixing bowl, combine the strawberry cake mix, guava juice, eggs, and coconut oil. Blend on low speed for 30 seconds, then medium speed for 2 minutes until smooth. Fill cupcake liners a third of the way and bake for 19-22 minutes or until a toothpick comes out clean. Let them cool.

In a mixing bowl, beat softened cream cheese with a hand mixer on medium speed until fluffy, about 2-3 minutes. Gradually add sugar and vanilla extract, mixing until well incorporated. Fold in the Cool Whip until smooth and refrigerate for about 15 minutes.

Once the mini Hawaiian guava cakes are cooled, spread the cream cheese frosting on top of each. Refrigerate for about 15-20 minutes to set the frosting. Drizzle or spread the cooled guava gel over the frosted cakes for a glossy finish.