Combine all the ingredients except vanilla in a small saucepan.

Cook the filling over medium-high heat, until the mixture starts to thicken, about 5 minutes.

Add vanilla, stir and leave it to cool to room temperature.

Take the butter from the fridge, cut it into cubes and let it sit for a few minutes. 

In a large bowl, whisk together the flour, salt, and sugar.

Sprinkle the cubed butter over the flour and squish it with your fingers.

Work the butter into the flour until you're left with pea-sized lumps of butter. 

Add the sour cream and using a fork incorporate it into the mixture.

Dump the dough onto a lightly floured surface and bring it together with a few quick kneads until you get a smooth ball, consistency of a Play-Doh - don't worry about over-working this dough. 

Split the dough in half, press each half into a disk and wrap tightly with plastic wrap.

Once the dough is wrapped into plastic, using a rolling pin, roll it over the dough to close any cracks.

Refrigerate for at least 2 hours.

Preheat the oven to 400 degrees F and line two baking sheets with parchment paper.

Take one half of the dough from the fridge and let it rest on the counter for 10-15 minutes, it will be easier to roll out.

Lightly flour the work surface and the rolling pin, and roll out the dough to about 1/8-inch thick.

Using a larger tree cookie cutter (mine was 5 inches high and 3.5 inches wide), you can use a star-shaped, or simple round cookie cutter if desired), cut out as many trees from the dough as you can.

Re-roll any scraps of dough and cut more.

On half of the cut trees, put about 1-2 teaspoons of filling straight through the middle (make sure the filling is not all over the edges), brush a little bit of water along the edges, then press all around the edge with your fingertips to seal then use a fork to crimp.

Poke each pie 3-4 times in the middle with a toothpick, brush with beaten egg and sprinkle with coarse sugar. 

Bake for 18-20 minutes (depending on the size of the pie itself), or until golden brown.

Repeat the process with the other half of the dough and the filling.

If desired, drizzle with glaze and sprinkles.

In a small bowl add powdered sugar and orange juice and whisk to combine.

If you want a thinner glaze add in more orange juice.

If you want a thicker glaze add in more powdered sugar.