Banana Blackberry Oatmeal Muffins

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Soft and tender Banana Blackberry Oatmeal Muffins are studded with fresh blackberries, scented with a hint of cinnamon and topped with an oatmeal streusel. These bakery-worthy muffins bake up tall, with domed tops, and has an addictively moist crumb!

Banana blackberry oatmeal muffins with oatmeal streusel stacked on a wire rack with fresh blackberries.

Muffins are a great on-the-go breakfast and these banana blackberry oatmeal muffins will surely become a favorite. Fresh blackberries are at peak season in July and August, so now is a great time to make these muffins. You can even make a double batch and freeze some, so you can enjoy later on.

For more bakery-style muffins, check out my blueberry chocolate chip muffins, small-batch banana muffins and triple chocolate muffins next!

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♡ Why You Will Love These Banana Blackberry Oatmeal Muffins
Ingredient Notes
Step-By-Step Instructions
💡 Tip
Substitutions & Variations
Key Equipment
Storage
⭐️ Expert Tips
FAQ
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♡ Did you try this recipe?
📖 Recipe

♡ Why You Will Love These Banana Blackberry Oatmeal Muffins

Big muffin tops. Letting the batter rest for an hour, overfilling the cupcake tin and baking the muffins in every other well, helps create those big domed tops.
Easy to make. There are very simple steps, plus no mixer is required.
So moist and tender. A combination of overripe bananas, sour cream, melted butter and oil, yields a moist and soft crumb.
Freezes well. You can read notes on how to freeze these muffins below in the "storage" section!

A pile of banana blackberry oatmeal muffins with oatmeal streusel stacked on a wire rack with fresh blackberries.

Ingredient Notes

Here are some notes about all the ingredients used in these Banana Blackberry Oatmeal Muffins. Quantities and full instructions are in the recipe card below!

Banana blackberry oatmeal muffins ingredients which include, flour, baking powder, baking soda, cinnamon, salt, bananas, eggs, oil, butter, sugar, vanilla, sour cream and fresh blackberries.

Banana Blackberry Muffins

All-Purpose Flour (Plain Flour) - I recommend using a kitchen scale to measure your flour with for the best results. Adding too much flour can make your muffins dry and dense rather than light and moist.
Baking Powder + Baking Soda - Adds lift and creates a light texture.
Salt - Round out the flavors.
Cinnamon - For flavor.
Banana - Make sure your bananas are ripe. Overripe bananas add natural sweetness and moisture.
Unsalted Butter + Oil - Butter adds flavor and the oil keeps the muffins moist.
White Granulated Sugar - For sweetness and moisture.
Eggs - Adds structure.
Vanilla Extract or Vanilla Paste - For flavor.
Sour Cream - Makes the muffins moist.
Blackberries - For the best flavor, use fresh ripe blackberries if you can.

Oatmeal Streusel Topping

All-Purpose Flour
Oats - You can use quick oats or rolled oats.
Brown Sugar - Adds a subtle molasses flavor that works well with banana.
Butter - We're using room temperature butter to work into the streusel.

*See recipe card for quantities.

Step-By-Step Instructions

Here are step-by-step photos and instructions on how to make these Banana Blackberry Oatmeal Muffins! Please find detailed instructions in the recipe card at the end of this post.

All-purpose flour, baking powder, baking soda, cinnamon and salt are in a glass mixing bowl.

Step 1. In a small bowl, whisk together flour, cinnamon, baking powder, baking soda and salt.

A person holding a fork mashing overripe bananas in a large glass bowl.

Step 2. In a large bowl, finley mash your banana.

Mashed bananas, eggs, sugar, oil, melted butter, vanilla and sour cream are in a large mixing bowl.

A person whisking wet ingredients in a large glass bowl.

Step 3. Add melted butter, oil, sugar, sour cream, eggs and vanilla, and whisk well to combine.

Dry ingredients are sifted into a bowl of wet ingredients.

Step 5. Sift dry ingredients into wet ingredients, and mix until just combined.

Flour coated blackberrie are added to a bowl of banana muffin batter.

Step 6. Gently fold in flour-coated blackberries, then cover and let the batter rest on the counter for 1 hour.

A person's hand combining flour, oats, brown sugar and butter in a small mixing bowl.

A person's hand holding oatmeal streusel crumble.

Step 7. Combine flour, oats and brown sugar in a small bowl. Add cubed butter, then using your finger tips, work the butter into the mixture until coarse crumbs form.

Oatmeal streusel topping is added on top of the banana blackberry muffin batter.

Step 9. Line a muffin pan with 6 paper liners, alternating every other well. Scoop and fill the liners, overfilling so the batter sits higher than the liner. Then top with streusel.

Banana blackberry oatmeal muffin baked in a muffin tin.

Step 10. Bake at 400ºF (204ºC) for 5 minutes and then lower the oven temperature to 350ºF (180ºC) and continue baking for 14 to 18 minutes. Cool and enjoy!

💡 Tip

For tall muffins, bake muffins in every other well. This allows more heat to circulate the muffins to help them rise taller as they bake.

A close up of the inside of a banana blackberry oatmeal muffins with oatmeal streusel sitting on a wire rack.

Substitutions & Variations

Sour Cream - You can easily replace with plain Greek yogurt.
Oil - Any neutral oil will work such as, avocado oil, canola oil, vegetable oil, grapeseed oil, refined coconut oil, sunflower oil or light olive oil.
Blackberries - Feel free to substitute with other berries such as blueberries, raspberries or strawberries.
Vanilla Extract - For a flavor variation, you can add 1 teaspoon pure almond extract.
Oats - If you don't have oats in your pantry, you can omit it.
Other Add-Ins - Feel free to add chopped nuts and chocolate chips.

Key Equipment

Bowls
Hand Whisk & Rubber Spatula
Digital Kitchen Scale - This is the scale I use (not an affiliate link).
Muffin Pan
Muffin Papers/Liners

Storage

Room Temperature - Store in an airtight container at room temperature for up to 3 days.
Refrigerator - Store in an airtight container for up to 5 days in the fridge.
Freezer - Cool muffins completely, then wrap each muffin in plastic wrap and store in a freezer bag for up to 2 months. Thaw at room temperature before enjoying!

A close up of a banana blackberry oatmeal muffins with oatmeal streusel sitting on a wire rack.

⭐️ Expert Tips

Use a kitchen scale to weigh all your ingredients. Baking in grams, rather than volume, is the best and most accurate way to bake! All my recipes include gram conversions based on King Arthur's Weight Chart.

If you are not using a kitchen scale, measure your flour correctly. Fluff and aerate your flour first, then spoon into your measuring cup and finally level off with the back of a butter knife. Do not pack it in as it will add too much flour.

Use room temperature ingredients to ensure a smooth batter. This includes the egg and sour cream.

Do not overmix the batter. Overmixing will activate the gluten in the flour and can make your muffins tough.

Overfill the muffin liners. For tall muffins with domed tops, you'll want to overfill the liners so the batter sits higher than the liner.

FAQ

Can I use frozen blackberries?

I have not tested these banana muffins with frozen blackberries, but I'm sure you could. You do not need to thaw them and may need to add a few extra minutes of baking.

Why are my muffins dense?

Adding too much flour or overmixing is usually the culprit. My #1 baking tip is to always use a kitchen scale to measure ingredients in grams to ensure accuracy.

Why are my muffins dry?

Overbaking or too much flour will make your muffins dry.

Why are my muffin tops flat?

Underfilling your muffins liners or expired leaveners can cause this.

♡ Did you try this recipe?

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