Are you familiar with the pyramid pan (silicone mat)? They work better for making dog training rteats than for their intended purpose. There are lots of good recipes online. Here's a link to one: https://eileenanddogs.com/2017/01/11...s-from-a-mold/
You can include a little cheese or bacon fat or peanut butter for extra flavor (add a teaspoon or two of flour if the mixture becomes greasy).
Substitute some of the flour with rice or oat flour, or grind up some oatmeal.
Replace the chicken with liver plus an additional egg, (by volume).
Cook to soften cut up carrots and green beans and puree them into the mix for a lighter calorie version.
and there is even a Facebook group with loads of treat recipes: https://www.facebook.com/groups/674422232757856/