Preheat oven to 375°F (190ºC). Spray or line a 12-cup standard muffin tin with paper liners.
In a medium mixing bowl, sift together the flour, baking powder, baking soda and salt. In the bowl of an electric mixer fitted with the whisk attachment, beat the butter and sugar together until creamy.
Add the eggs, one at a time, beating well after each addition. Add the vanilla and continue to mix until combined.
Alternate slowly adding the flour mixture and the buttermilk to the egg mixture, beginning and ending with the flour. Mix until completely combined and smooth. Using a rubber spatula gently fold in the lemon curd and then the blueberries.
Divide the batter among the prepared cups, filling each cup to the top. Sprinkle the streusel crumb topping over each muffin as well as the turbinado sugar.
Bake until the muffins are golden brown on top, about 25 to 30 minutes, rotating the pan halfway through cooking.
Remove the muffins to a wire rack to cool. Serve warm or at room temperature.