Preheat the oven to 190°C (375°F) and line or grease a muffin tin.
In a large bowl, whisk together the flour, sugar, cocoa, baking powder, baking soda, and salt. Make a well in the centre.
Pour the milk and olive oil to the centre of the bowl and gently mix until just combined. Don't over mix.
Add the raspberries and fold until they're evenly incorporated throughout the batter.
Add the batter into the prepared muffin tin, filling each tin about evenly. They should be right around three-quarters full. Top each muffin with a couple of extra raspberries if you'd like.
Bake for 18-20 minutes, or until the muffins spring back lightly when touched and a toothpick inserted into the middle of a muffin comes out clean.
Cool the muffins in the tin for 5 minutes before carefully removing and cooling fully on a rack. Keep the muffins in a sealed container in a cool room or the refrigerator for 3-4 days, or freeze up to 2 months.