Apricot Bavarian Cream Cake

To prepare cake layers: Butter the bottom and sides of two 9-inch round cake pans; line the bottoms with parchment paper. Preheat oven to 350 degrees F.

Combine milk and 4 tablespoons butter in a small saucepan. Heat over low heat until the butter is just melted. Set the pan aside.

Stir flour and baking powder together, then sift onto a piece of parchment paper.

Whisk eggs in a mixing bowl by hand to combine, then whisk in salt. Whisk in sugar in a stream, then whisk in vanilla. Then, using a hand-held electric mixer or a stand mixer with the whisk attachment, whip the mixture on medium-high speed until lighter in color and very light and fluffy in texture, about 3 minutes in a stand mixer or 5 minutes with a hand mixer.

Gently whisk in the warm milk mixture by hand. Add the flour mixture in 4 additions, lifting the parchment paper to help you sprinkle it in. Use the whisk as you would a rubber spatula to fold the flour into the liquid, gently whisking to incorporate each time. Divide the batter between the prepared pans and smooth the tops.

Bake in the center of the oven until golden and firm when touched in the center, about 20 minutes. Let cool in the pans on a wire racks for 10 minutes.

Run a sharp paring knife around the layers to loosen, then invert the pans onto the racks.

Immediately turn the layers over so they cool with the paper on the bottom. Let cool completely.

To prepare syrup: Combine 1/3 cup water and 1/4 cup sugar in a small saucepan; bring to a boil, stirring to dissolve the sugar. Pour into a small heatproof bowl and cool for 15 minutes. Stir in rum (or water-almond extract mixture) and vanilla. Set aside.

To prepare apricot puree: Combine apricots, 1 cup sugar and 1/2 cup apricot nectar (or water) in a large saucepan; bring to a boil over medium heat. Reduce heat to a simmer, cover and cook, stirring occasionally, until the apricots have completely disintegrated, 25 to 30 minutes. Let cool for 15 minutes. Transfer to a blender or food processor and process until smooth. Pour into a large bowl and let cool to room temperature. (Or loosely cover and refrigerate for up to 3 days. If refrigerated, let stand at room temperature for 2 hours before continuing.)

To prepare apricot cream: Pour the remaining 1/2 cup apricot nectar (or water) into a small heatproof glass bowl and sprinkle with gelatin; let stand until the gelatin is softened, about 3 minutes. Microwave uncovered, on High, until the gelatin is dissolved but the liquid is not boiling, 20 to 40 seconds. (Alternatively, heat 1 inch of water in a small skillet over medium-low heat; set the bowl in the pan and stir until the gelatin is dissolved.) Whisk 1 cup of the apricot puree into the dissolved gelatin to cool it, then whisk that mixture into the remaining puree.

Beat heavy cream with an electric mixer in a medium bowl until firm peaks form. Fold in yogurt. Gently fold the yogurt-cream into the apricot mixture with a whisk.

To assemble cake: Coat the bottom and sides of a 10-inch springform pan with cooking spray.

Using a large serrated knife, trim off the very top of each cake layer so the tops are flat. Brush the top of each layer with half of the reserved syrup. Place one layer in the center of the prepared springform pan (see Tips). Pour half the apricot cream over the layer; use an offset spatula to spread the apricot cream over the top and down the sides of the cake. Quickly center the second layer on top. Pour the remaining apricot cream over the cake until it reaches the top of the pan; you may have a little left. Use the offset spatula to spread the cream evenly over the top. The pan should be very full, but not overflowing.

Refrigerate the cake until the apricot cream is firm, about 1 hour. Loosely cover with plastic wrap and continue chilling until completely set, about 7 more hours.

To serve: Run a thin paring knife between the cake and the side of the pan to loosen. Remove the side of the pan. Use 2 wide, sturdy spatulas to slide the cake off the pan bottom and onto a serving plate.

To decorate: Smooth any lines on the sides of the cake with the back of a spoon, if desired. Decorate the top with apricot wedges and white chocolate curls, if desired.