Line an 8x8-inch pan with parchment paper leaving a 2-inch overhang along each side.

Spread oats, chopped cashews and almonds out in an even layer on a large baking sheet and place in the oven. Turn the oven on at 325°F and let it preheat. By the time it is ready, the oats and nuts should be gently toasted. If they still don’t seem to have any colour on them, leave them in for another 5 minutes while watching carefully so that they don’t burn. Transfer them to a large bowl. Add dried cranberries, raisins and sunflower seeds and set aside.

Combine honey, brown sugar and olive oil in a small saucepan over medium heat and stir until it just comes to a simmer. Stir in salt, cinnamon and ground flax seeds, then pour it over the oat mixture in the bowl. Stir until everything is evenly coated.

Scrape the sticky mixture into the prepared pan and press it down firmly in an even layer. Use the bottom of a measuring cup to make an even compact slab, running it firmly back and forth over the mixture. Bake for 15-18 minutes until lightly golden around the edges and the surface is slightly puffed. It shouldn’t feel too hard, but rather slightly soft when gently pressed. Do not over-bake or it will be hard once cooled and difficult to slice.

Transfer pan to a wire rack and immediately pack the granola down again while still hot using the bottom of a measuring cup. This will ensure that it holds together when sliced. Let the slab cool completely in the pan before slicing, then dip the bottom side in melted dark chocolate. Drizzle more dark chocolate over top and let set before storing in an airtight container at room temperature for up to 2 weeks.