Preheat the oven to 350°F. Prepare a 12-cup muffin tin with liners.
For the topping, add the flour, brown sugar, and salt to a medium bowl and mix well. Add the butter and mix until large clumps form. Press the mixture together in the bowl, then place in the refrigerator until ready to use.
For the muffin batter, mix the flour, baking powder, baking soda, cinnamon, and salt in a large bowl and set aside.
Use a stand or hand mixer to beat the olive oil, dark brown sugar, granulated sugar, and eggs until the sugar has dissolved and the mixture is light and fluffy, about 5 minutes.
In the meantime, combine the eggs, milk, yogurt, and vanilla extract in a large mixing cup until well-blended.
When the olive oil mixture is ready, turn the mixer speed to low. Add ⅓ of the flour mixture, then stir until a few dry streaks remain. Next, add ½ of the milk mixture and stir until combined. Repeat, alternating flour with the milk, and ending with the last bit of flour.
When just a few dry streaks remain, stir in the apples. Fill each muffin cup just below the top, then sprinkle the crumb mixture on top and gently press into the batter.
Bake the muffins for 25-30 minutes, until a toothpick inserted in the center comes out clean.
Immediately remove the muffins from the pan and let them cool completely on a wire rack.
Preheat the oven to 350°F. Prepare a 12-cup muffin tin with liners.
For the topping, add the flour, brown sugar, and salt to a medium bowl and mix well. Add the butter and mix until large clumps form. Press the mixture together in the bowl, then place in the refrigerator until ready to use.
For the muffin batter, mix the flour, baking powder, baking soda, cinnamon, and salt in a large bowl and set aside.
Use a stand or hand mixer to beat the olive oil, dark brown sugar, granulated sugar, and eggs until the sugar has dissolved and the mixture is light and fluffy, about 5 minutes.
In the meantime, combine the eggs, milk, yogurt, and vanilla extract in a large mixing cup until well-blended.
When the olive oil mixture is ready, turn the mixer speed to low. Add ⅓ of the flour mixture, then stir until a few dry streaks remain. Next, add ½ of the milk mixture and stir until combined. Repeat, alternating flour with the milk, and ending with the last bit of flour.
When just a few dry streaks remain, stir in the apples. Fill each muffin cup just below the top, then sprinkle the crumb mixture on top and gently press into the batter.
Bake the muffins for 25-30 minutes, until a toothpick inserted in the center comes out clean.
Immediately remove the muffins from the pan and let them cool completely on a wire rack.