Preheat oven to 400 degrees. Grease a muffin tin or line with muffin liners.
Add flour, sugar, salt and baking powder to a large bowl. Whisk to combine.
Add oil to a 1 cup measuring cup. Add egg and enough milk (⅓ - ½ cup) to fill to 1-cup line. Add vanilla and almond extract (if using) and whisk to combine.
Add to flour mixture and stir until just combined. Then fold in blackberries.
To Make Streusel Topping: Mix together sugar, flour, butter, cinnamon and cardamom with a fork until coarse crumbs form. Sprinkle over muffins before baking.
Divide batter evenly into muffin cups. Sprinkle with streusel topping.
Bake for 20-25 minutes, until a tester inserted into the center comes out clean. When muffins are done, cool for a few minutes in the muffin pan before removing to cool on a wire rack.
Video
Notes
How to make ahead & store
To store, place them in a plastic bag or airtight container lined with a paper towel (this prevents them from getting soggy). Seal and store at room temperature for up to 4 days.
Recipe tips
I used both cinnamon and cardamom in the crumble topping for these blackberry muffins because I love the flavor cardamom gives baked goods. However, if you don’t have cardamom, or don’t love its flavor, feel free to leave it out and just use 1 ½ teaspoons of cinnamon instead.
I used both vanilla and almond extracts in these bakery style blackberry muffins. I love how the almond extract complements the berries, but you can leave out the almond extract and use 1 ¼ teaspoons vanilla extract.
This blackberry muffin recipe will make 8 large muffins, or 10 standard size muffins. Cook time will vary based on the size of your muffins, so be sure to check them for doneness. They are done when a tester inserted into the center comes out clean.
Variations
You can also make these muffins with raspberries, blueberries or strawberries.
This recipe can be adapted to make mini muffins. Simply reduce the baking time if you’re using mini muffin tins.
Add a little tang to your muffins by adding in a squeeze of lemon juice and some lemon zest.