Heat your oven to 425 degrees Fahrenheit. Place paper liners in a 12-count cupcake pan and set it aside.

For the crumb topping, mix flour, sugar, brown sugar, and salt. Add melted butter and stir with a fork until you have coarse crumbs. Set this aside.

To make the lemon muffins, whisk together the dry ingredients (flour, baking soda, baking powder, and salt) and set them aside.

In a big bowl, blend softened butter and sugar for about 2 minutes at high speed. Then, add eggs, lemon zest, vanilla, and lemon extract, and mix for another 2 minutes. Add Greek yogurt and lemon juice, and mix just until combined. With your mixer on low, mix in the dry ingredients.

To prepare the creamy filling, blend softened cream cheese, sugar, and vanilla until well mixed.

Now, for the assemble muffins, spoon 1 heaping tbsp of the muffin batter into each cup. Put 1 tbsp of the cream cheese mix in the middle of each muffin. Cover the cream cheese with more muffin batter, filling each cup about two-thirds to three-quarters full.

Finally, generously sprinkle streusel crumbs on top of each muffin.

Place the muffins in the preheated oven and lower the temperature to 350°F. Bake for 25 minutes or until the tops turn golden brown and the center is set.

Let the muffins cool for 5-10 minutes in the pan, then transfer them to a rack to cool completely.

While the muffins are cooling, make the glaze. Mix powdered sugar with lemon juice. Begin with 1 tsp of juice and add more gradually until you achieve the desired thickness. Drizzle the glaze over the muffins and serve.