Adjust oven rack to middle position and heat oven to 350 degrees.

Grease 9 by 5-inch loaf pan (or a 5.5 x 2.75 inch) with 1 tablespoon softened butter; dust with 1 tablespoon cake flour, tapping out excess.

In medium bowl, whisk together flour, baking powder, and salt; set aside.

In glass measuring cup or microwave-safe bowl, microwave butter, covered with plastic wrap, at full power until melted, 1 to 2 minutes. (Alternatively, melt butter in small saucepan over medium heat.)

Whisk melted butter thoroughly to re-incorporate any separated milk solids.

In a food processor, process sugar and zest until combined, about five 1-second pulses.

Add lemon juice, eggs, and vanilla; process until combined, about 5 seconds.

With machine running, add melted butter through feed tube in steady stream (this should take about 20 seconds).

Transfer mixture to large bowl.

Sift flour mixture over eggs in three steps, whisking gently after each addition until just combined.

Pour batter into prepared pans and bake 15 minutes.

Reduce oven temperature to 325 degrees and continue to bake until deep golden brown and skewer inserted in center comes out clean, about 35 minutes, rotating pan halfway through baking time.

Cool in pan for 10 minutes, then turn onto wire rack.

Once cooled, slice cake into half inch slices.

Place the cake slices under a broiler until “toasted”. Remove and set aside to cool.

Use a cookie cutter just smaller than the sliced cake and cut out a circle of the panna cotta. Once the cakes have cooled, place the panna cotta on top.

Cut out a medium size tip on the mango curd piping bag. Pipe a round mound of the mango on top and centered on the panna cotta.

Voila, your egg on toast is ready.

Serve and enjoy!