In a large bowl, mix all the ingredients until well combined. Evenly press 2/3 of the dough into the prepared baking dish.
Top the crust with a thick layer of the guava jam making sure it is evenly spread over the crust.
Sprinkle the remaining dough on top of the guava jam so it looks like a crumble topping. Bake the bars for 35-38 minutes or until golden brown. Enjoy!