Here is what you can do to prevent the bars from falling apart. 1. Use good quality oats and flour and mix with enough liquid (oil and honey) to help bind the mixture together. 2. Press the mixture firmly and tight into the baking pan. 3. Bake till it's done, slightly golden around the edges. 4. Wait until it cools to slice. You can even refrigerate before slicing. Even after this if your bars are crumbling, add a teaspoon of chia seeds to the mixture next time and try the recipe.