This buttery cake is a spectacular springtime dessert. Scented with orange, the interior combines luscious fresh strawberries with an easy mascarpone filling.
Preheat the oven to 350°F. Grease a 9" springform pan.
To make the cake: In a medium bowl whisk together the flour, baking powder, baking soda, and salt.
In a large mixing bowl or the bowl of a stand mixer, beat the butter and sugar until light and fluffy. Beat in the eggs one at a time; stop and scrape the sides and bottom of the bowl after the second egg has been added, mixing briefly to incorporate any sticky residue. Stir in the vanilla and Fiori di Sicilia.
Add the dry ingredients to the batter alternately with the sour cream, mixing just until combined.
Spread the batter in the prepared pan, leveling the top with a spatula or knife.
Bake the cake for 40 to 45 minutes, until a toothpick inserted in the center comes out clean.
Remove the cake from the oven and cool for 10 minutes. Run a thin blade around the edge to free it from the sides, then unclip the springform and remove the cake. Transfer it to a rack to cool completely.
To make the filling: Beat the heavy cream until soft peaks form. Stir together 1/3 cup (66g) of the sugar and the ClearJel and add to the cream. Beat until stiff peaks form.
Remove 1 1/2 cups of the whipped cream and set aside to decorate the top. In a separate bowl, beat the mascarpone with the remaining sugar, vanilla, orange oil, and liqueur until smooth. Fold the whipped cream into the cheese mixture.
To assemble the cake: With a serrated knife, split the cake layer in half horizontally. Remove the top half and set it aside. Return the bottom half to the base of the springform pan.
Replace the sides of the springform pan and clip closed around the cake. Slice strawberries in half vertically, placing them on top of the cake with the cut sides against the sides of the pan.
Fill the center of the cake with whole berries, trimming the tops so they’re shorter than the rim of the pan. Spread the filling over the berries; tap the pan on the counter to fill in any gaps.
Replace the top layer, cut side down. Pipe or spread the reserved whipped cream over the top of the cake. Decorate with additional strawberries, if desired.
For best results, serve the cake the same day it’s made. Store any leftover cake, well wrapped, up to a day or two in the refrigerator.
What if you don't have the called-for Instant ClearJel for the filling? You can omit it but the cake won't slice as cleanly; the filling will tend to slump.
