Prepare the praline cream:

In a bowl, whisk together the egg, egg yolk, and sugar. Add the cornstarch.

In a saucepan, bring the milk to a boil. Gradually add the egg and sugar mixture, whisking constantly. Cook until thickened.

Remove from heat and add the butter and praline chocolate. Whisk well until smooth. Chill in the refrigerator.

For the choux pastry:

In a saucepan, combine the water, milk, butter, and sugar. Bring to a boil.

Add all the flour at once and stir with a wooden spoon until the dough forms a ball and pulls away from the sides.

Let cool slightly, then add the eggs one at a time, mixing well after each addition.

Transfer the dough to a piping bag and pipe choux about 1 1/2 inches wide (4 cm) in a ring about 9 inches (22 cm) in diameter.

Mix the egg yolk with a little water and brush over the choux with a pastry brush.

Sprinkle sliced almonds on top and bake for about 25 minutes at 340°F (170°C).

Once baked, let cool completely.

Slice the ring in half horizontally.

Fill the bottom half with the praline cream.

Place the top half back on and dust with powdered sugar.