This sweet, subtly tropical-flavored bread is a lovely for breakfast with coffee, or after dinner for dessert. And any time in-between, of course!
Preheat the oven to 350° F, and use 1 teaspoon of the melted butter to grease a bread pan that’s approximately 8 1/2 x 4 1/2 x 2 3/4-inches. Set aside.
Cut the guavas in half, and use a small spoon to scoop out the flesh -- you need 2 cups of it. Add it to a blender and blend until you have a smooth purée, about 10 seconds on high.
Over a bowl or measuring glass, add the puréed guava flesh to a fine mesh strainer and use the back of a large spoon or rubber spatula to stir and gently press the flesh and seeds against the strainer, so the juice can easily pass through without the seeds. Do this until next no more juice strains out. You need 3/4 cup.
Remove 1/4 cup of the juice and add it to small saucepan. Set aside. Pour the remaining juice into a large mixing bowl.
Add the pineapple to the guava juice in the mixing bowl, along with the eggs, brown sugar and vanilla. Stir until you have as smooth a mixture as possible.
In a second mixing bowl, evenly combine the flour, baking powder, salt and allspice.
Fold the wet ingredients into the dry, fold in the remaining 1/2 cup of the melted butter, and pour the batter in the prepared pan.
Place the pan in the preheated 350° F oven and bake until it’s completely solid and doesn't move when jiggled, about 50 minutes. It should be golden brown and cracking on top. Let it cool for at least 30 minutes.
While the bread is baking, gradually sift the powdered sugar into the saucepan with the guava juice, whisking as you go. Add enough of the sugar so that it’s thicker, but pourable. Liquid can absorb a lot of powdered sugar! Place the pan over low heat and continue to whisk until there are no lumps.
Once the bread has cooled to room temperature, drizzle it with the glaze. (You will likely have more than enough.)
Slice and serve.