Start by making the syrup. In a small saucepan, combine the caster sugar, dark rum, freshly squeezed lemon juice, purified water, and a few drops of orange blossom water.

Heat gently on low until the sugar dissolves and the mixture thickens slightly. This shouldn’t take long, about 5 minutes. Once it’s done, set it aside to cool.

While the syrup cools, toast your sliced almonds. Heat a dry skillet over medium heat. Add the sliced almonds and toast them, stirring frequently. Keep an eye on them as they can burn easily. You want them golden and fragrant, which should take about 3-5 minutes.

In a medium bowl, combine the almond meal, superfine sugar, vanilla bean paste, almond essence, fine sea salt, orange rind, and the egg. Beat until smooth. This mixture should resemble a thick paste. The delightful aroma of almond and citrus will already start to fill your kitchen.

Grab your brioche slices, which should be slightly dried out. You want them to absorb the almond mixture but not become soggy. Place them on a baking tray lined with parchment paper. Spread a generous layer of orange preserves or your chosen jam over each slice.

Now, dollop the almond mixture over each slice of brioche, allowing it to be generously spread. It’s okay if some drips over the edges. Remember, nobody can resist a little extra goodness.

Preheat your oven to 180°C (350°F). Once it's hot, bake the brioche slices for about 20-25 minutes or until they’re golden and the almond topping is slightly puffed up. Your kitchen will smell heavenly!

Once out of the oven, brush the prepared syrup over each slice while they are still warm. This adds a glossy finish and further enhances the flavor. Finish off with the toasted almonds, scattering them generously over the top.

Let the pastries cool slightly before serving. If you want to take it up a notch, dust with powdered icing sugar or add gold flakes for a touch of elegance.