Grease and line a 9 inch cake pan with parchment paper.
In a large bowl, combine the oats, seeds, nuts and grated apple.
In a small saucepan, melt butter, sugar and syrup over low heat. Remove from heat and pour onto the oat mixture. Gently mix to incorporate the ingredients.
Press half of the mixture into the pan using a spoon or rubber spatula. Then top with the mashed blackberries.
Finish with the other half of the oat mixture. Gently press with a spatula.
Bake from 25 to 28 minutes or until the top is nicely browned.
Let cool in the pan before serving. Refrigerate leftovers. Yum!
Recipe by The Gluten Free at https://www.theglutenfree.com/gluten-free-blackberry-and-apple-flapjack/