• Preheat oven to 375 degrees.
• Line 12 regular size muffin tins with cupcake liners or spray with non-stick spray.
• In a large mixing bowl whisk together the cake flour, granulated sugar, baking powder, and salt together.
• In a medium mixing bowl, whisk egg, milk, avocado oil,  Greek yogurt, and vanilla extract until combined.
• Add the wet ingredients to the dry ingredients in the large mixing bowl.  Stir just until ingredients are combined. Do not overmix the batter.
• Add the semi-sweet chocolate chips and fold into the batter.
• Gently fold the raspberries into the batter.
• Fill the muffin liners 2/3 full with the batter.  Don't overfill them.

Streusel Topping:

• In a small bowl mix flour, granulated sugar and a pinch of salt together.  Add the melted butter and mix in with a fork until topping is crumbly.
• Sprinkle the streusel topping evenly over the muffin batter.
• Bake the muffins for 18-23 minutes or until the muffins and streusel topping are golden brown or until a toothpick inserted in the center of the muffin comes out clean.
• Cool the muffins on a wire rack.  You may eat the muffins warm or you can cool them to room temperature.
• Muffins can be stored at room temperature for 3-4 days.  They also freeze well for up to 3 months.  Just unthaw them and reheat for 10 seconds in the microwave.