Add the frozen raspberries, sugar, and orange juice to a medium saucepan. Cook over medium heat, stirring occasionally, until the sugar dissolves and the mixture begins to simmer. Use a spatula or spoon to break the raspberries down into smaller pieces.

Continue simmering the jam for 5-7 minutes, stirring frequently until the mixture thickens slightly and coats the back of a spoon. The jam will continue to thicken as it cools.

Remove the saucepan from the heat and let the jam cool to room temperature. Transfer it to a heat-proof jar or bowl, cover, and refrigerate until completely chilled before filling the cupcakes.

Place the white chocolate in a medium heat-proof bowl and set aside.

Add ½ cup (120g) of the heavy cream to a small saucepan. Heat over medium-low heat (or microwave) until steaming and just beginning to simmer around the edges. Do not let it come to a full boil.

Pour the hot cream over the white chocolate, then let it sit undisturbed for 1 minute to soften the chocolate.

Add the remaining cold heavy cream, orange juice, and orange zest. Whisk slowly from the center outward until the ganache is completely smooth and no lumps of chocolate remain. If needed, microwave the mixture in 10-second intervals, stirring well between each, until fully melted and smooth.

Press a piece of plastic wrap directly onto the surface of the ganache to prevent a skin from forming. Refrigerate for 3-4 hours. The ganache will still look thin and liquidy, which is normal.

Preheat the oven to 350°F. Line a 12-cup cupcake pan with paper liners and set aside.

Add the sugar and orange zest to a large mixing bowl. Use your fingertips to rub the zest into the sugar until the sugar feels slightly damp and very fragrant. This helps release the natural oils from the zest for stronger orange flavor.

Add the flour, baking powder, and salt and whisk until combined.

Add the softened butter and oil to the dry ingredients. Using an electric mixer on low speed, mix until the butter is fully incorporated and the mixture resembles wet sand with no large chunks of butter remaining.

Add the eggs and vanilla extract and mix on medium-low speed until combined.

Add the sour cream, milk, and orange juice. Mix just until the batter is smooth and fully combined, scraping down the sides and bottom of the bowl as needed.

Divide the batter evenly between the cupcake liners, filling each about ⅔ full.

Bake for 13-15 minutes, or until the tops spring back lightly when touched and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the cupcakes cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely before filling and frosting.

Once cooled, use a cupcake corer or small knife to remove the centers of each cupcake. Fill each cupcake with raspberry jam, then place the cut-out cupcake pieces back on top to cover the filling.

Frost the cupcakes with the whipped orange ganache using a piping bag or offset spatula. Garnish with fresh raspberries if desired.