Preheat the oven to 350F (325F if using a convection oven). Line an 8 inch square cake pan with parchment paper.
Measure and sift all dry ingredients (almond and coconut flours, protein powder, baking powder and salt) in a bowl and set aside.
Melt the butter and whisk in the sweeteners. Mix until you obtain a creamy consistency.
Then continue to mix while adding one egg at a time until all eggs are incorporated.
Add the Greek yogurt and almond extract and continue to mix until you obtain a soft mixture without lumps.
Slowly start adding the dry ingredients that you set aside earlier and continue to mix until all ingredients are incorporated.
Pour half of the batter on the lined cake pan.
Thinly slice the guava paste and cream cheese. Cover the batter with the slices alternating between guava paste and cream cheese.
Cover the guava and cream cheese with the rest of the batter.
Bake for 20 to 25 minutes