Preheat your oven to 375°F (190°C) and line a muffin pan with paper liners.

In a medium saucepan, combine fresh strawberries, sugar, and lemon juice. Cook for about 5-7 minutes until softened.

In a mixing bowl, whisk together flour, sugar, and cinnamon. Add softened butter and mix to resemble crumbs.

In a large bowl, combine melted butter, sugar, Greek yogurt, eggs, milk, and vanilla extract. Fold in flour, baking powder, and salt.

Spoon half of the batter into the muffin cups, add strawberry filling, then top with remaining batter and crumble.

Bake for 20-25 minutes for jumbo muffins, or 15-22 minutes for standard muffins until a toothpick comes out clean.

Prepare the creamy filling by whisking eggs and sugar over a double boiler until it reaches 160°F (70°C). Mix in mascarpone and vanilla.

Once cooled, carve out a bit from each muffin and pipe in the mascarpone filling. Replace tops to encase the filling.