In a small bowl, combine warm water, yeast, and 1 teaspoon of sugar. Mix well and let it rest about five minutes, or until yeast has bloomed/foamed up. (if your yeast has not bloomed/foamed up by this point, your water was too warm or your yeast is dead).

In a large mixing bowl, combine the flour, kosher salt and sugar. Mix well to combine.

Add the eggs, olive oil and yeast/water mixture. Stir with a dough whisk or wooden spoon or dough whisk to create a rough, shaggy dough.

Pour the dough onto a clean kitchen counter and begin kneading the dough by pushing the dough with the palm of your hands, dragging it forward on the counter, and then folding it back over itself. Give it a quarter turn between each knead.

Depending on the weather, the dough may be sticky, so add a little additional flour as you knead (anywhere from ¼ -⅓ cup), until the dough is slightly smooth and supple, but still has a little tackiness left.

Lightly coat your mixing bowl in olive oil, a few tablespoons. Put the dough in the bowl and give it a little swirl around the bowl. Flip the dough over so all sides have been covered with oil.

Wrap the bowl in plastic wrap, cover in a towel, and let the dough rise in a warm place for 45 minutes, until the dough has doubled in size.

After 45 minutes, fold and punch the dough dough four times, giving the dough a quarter turn between each fold and punch.

Cover the dough back up and allow it to rise another 35 minutes.

In a small bowl, combine the soft (but not melted) butter and clementine zest until fully incorporated.

Add the flour and mix until fully combined. Set aside.

In a bowl of a food processor, combine the almond flour, powdered sugar, almond extract, liquor/rum, and kosher salt.

Pulse the processor a few good whirls until the ingredients are fully combined.

With the processor running on low, slowly drizzle in the water and let it mix until the marzipan forms. The consistency should be spreadable, but not dry. Place marzipan in a bowl and set aside.

Preheat your oven to 350 degrees.

Divide the dough in half, sprinkle it in flour and cover with a towel. Allow the dough to rest for five minutes.

Lightly flour the counter and roll out the first piece of dough into a 13x20 rectangle. (The dough will be rolled out very thin, that’s what you want.) Position the dough so the long part of the dough (20”) is parallel to the edge of your counter.

Dot the dough with half of the butter mixture. Using an offset spatula or butter knife, very carefully spread the butter all over the dough in an even layer. Do not leave a border.

Dot the dough with half of the marzipan. Using an offset spatula or butter knife, very carefully spread the marzipan over the butter into an even layer. Do not leave a border.

Carefully roll the dough snugly towards you (like making cinnamon buns) until you have a long rope.

Set the dough rope aside and repeat the process with the other half of dough and filling.

Twist the two dough ropes together and secure them to each other, creating a circle.

Place the challah in a well greased angel food cake pan, cover and let rise in a warm place until doubled. To make sure the dough is ready, poke the dough with your finger, when the dough doesn’t spring back, it’s fully proofed.

Combine the egg yolk and ½ teaspoon of water in a bowl and mix together. Brush the challah with the egg wash and allow it to dry for one minute. Brush on a second layer and scatter generously with sliced almonds.

Bake for 35 - 40 minutes until deeply golden. If parts of the top begin burning or turn too dark before the challah is finished baking, loosely top those areas with small pieces of aluminum foil while the challah continues baking.

Remove the challah from the oven and allow it to cool for 10 minutes.

Carefully turn the challah out from the pan onto a cooling rack. Allow it to cool thoroughly before serving.

Optional: before serving, lightly sprinkle the top with powdered sugar.