Heat your oven to 350°F (180°C) and line the cupcake pan with paper liners for a mess-free bake.
In a big bowl, whisk together oil, sugars, eggs, and vanilla until smooth and glossy. Fold in the applesauce, it adds moisture and subtle apple flavor.
In another bowl, mix flour, cornstarch (for soft crumb), baking powder, baking soda, salt, cinnamon, and ginger well.
Pour the dry ingredients and buttermilk into the wet mix gradually, folding them in just until blended, overworking will flatten the batter.
Fill liners about ¾ full and bake for 18 minutes. Use a toothpick to check, clean or a few crumbs mean they’re done.
Cool cupcakes in the pan for 5 minutes, then transfer to a wire rack to cool fully before frosting.
For the filling, toss apples with cinnamon and lemon juice. Cook in butter, brown sugar, and vanilla on low until soft and caramelized (around 7 minutes). Let cool.
Chill the bowl, then whip together mascarpone, powdered sugar, and cold cream until soft, creamy peaks form.
Frost the cooled cupcakes, leaving a little well in the center. Add the apple filling in for the perfect finishing touch on each bite.