While both muesli and granola are a mix of grains, seeds, nuts and dried fruits, the main difference is that granola is sweetened with honey or maple syrup and is baked. Muesli is not baked.
They each are regarded as a healthy breakfast.
Traditionally in Europe this cake is made after breakfast, once you have rounded up all the strawberries in the patch and brought the spoils back inside.
I have adapted the recipe to be gluten-free. I have found that adding almond butter makes a fluffier sponge and that yogurt, sour cream or thickened cream all work great in the recipe, so you can use whatever you have in your fridge.