• Line a muffin tin with cupcake liners. Set aside. Heat the oven to 375 degrees.
• In the bowl of your stand mixer, add the butter and sugar. Beat until the two are evenly creamed together.
• Add in the egg and vanilla, and mix again until evenly combined.
• In a separate bowl add the flour, baking powder, & salt. Use a fork to whisk them together until evenly combined.
• Alternate, adding some of the flour mixture then the buttermilk and slowly mixing the whole way. Wait until completely incorporated until you start with the next round.
• Once it's all in the main mixing bowl, mix again just until you're sure it's all evenly combined.
• Using a spatula fold in the all but a couple of the strawberries. Set the rest aside.

To Make The Muffins

• Add 1/4 cup of batter to each lined muffin tin. Continue until all the liners have been filled.
• Add the remaining diced strawberries out evenly onto the tops of the filled cups.

To Make The Crumble Topping

• In a medium sized mixing bowl, add all of the crumble topping ingredients.
• Mix them together using a sturdy spoon until everything's evenly incorporated and resembles an actual 'crumble'.
• Sprinkle the crumble evenly out on top of the filled muffins.
• Reduce the heat to 350 degrees and bake the muffins for 18-20 minutes.
• Let the muffins cool for 5 minutes before removing them from the pan.