Preheat the oven to 350 degrees.

Line a 10 inch springform pan with foil taking care to make sure that there are no tears or holes in the foil. (I place one piece of foil on the inside and one on the outside because otherwise it drips!)

Combine the dark brown sugar, water, and honey for the almond crunch topping. Mix well and pour into the bottom of the foil lined pan. Sprinkle evenly with the almonds. Set aside.

In a large bowl cream the butter and sugar. Add in the eggs and mix well. Stir in the vanilla.

In a medium bowl combine the flour, baking powder, and salt. In another medium bowl combine the milk and honey. Stir half of the flour mixture into the butter mixture and mix well. Add in the milk and honey and stir until combined. Add in the remaining flour and mix well.

Carefully pour the cake batter into the cake pan, taking care to pour it over top of the almond mixture.

Bake for 75-90 minutes or until the cake is golden brown and a toothpick inserted into the center comes out clean.

Remove the pan from the oven and run a butter knife around the edges. Let the cake cool for 10 minutes.

Carefully remove the sides of the springform pan. Place a wire cooling rack on top of the cake and flip it over. Peel the aluminum foil off the cake. Allow the cake to cool for 3 hours.

Meanwhile, make the pastry cream. Cut the vanilla bean in half lengthwise. In a saucepan heat the milk and vanilla bean over medium heat. Heat until steaming but not boiling. Pour the milk into a liquid measuring cup with a spout and remove the vanilla bean.

Rinse the saucepan with cool water and wipe dry. Off the heat whisk the egg yolks and sugar for 2-3 minutes, until pale.

Whisk in the cornstarch and salt. Drizzle in the milk mixture while whisking constantly, until all of the milk is added.

Return the mixture to medium heat and stir constantly until it begins to bubble. Reduce heat to a simmer and stir constantly for 2-3 minutes or until thickened.

Immediately remove from heat and whisk in the butter. Place in a bowl and refrigerate until ready to use.

Using a serrated knife cut the cake in half. Pipe the pastry cream into the center of the cake and use a butter knife to smooth. Replace the top half of the cake.

In a large bowl beat the heavy cream until it begins to thicken. Add in the powdered sugar, rum, and vanilla. Continue beating until the whipped cream is thick.

Carefully spread the whipped cream over top of the cake. If desired chop some leftover almonds and sprinkle them around the outer edge of the cake on the whipped topping.

Store in the refrigerator for up to 3 days. Cake is best served the day it is put together.