No secret, would love to share.
Some people use water or milk to 'extend out' the eggs, but not me. I use eggs, the flavored coffee creamer, vanilla and cinnamon. I really like when I use the coffee mate coconut creamer, there is just a hint of that flavor when you're eating it.
That's the standard batter. Now, if you are making your own bread, cut the slices THICK. I make a filling of ricotta cheese with some sugar, and I pipe the filling into the pocket using a pastry bag. Make a pocket through the side and still keeping it intact. Then, I use my batter.
Sometimes when I make banana bread from scratch, I just cut slices of the banana bread, then the batter. I dust it with a little powdered sugar before serving.
When I have fresh blueberries, I mascerate them in some sugar, let it sit a few hours, then put it in a pot, bring it to a boil then thicken it up with a cornstarch slurry. It will resemble the consistency of pie filling, nice and thick.