Macaron Shells

1. Line 2-3 baking sheets with parchment paper or silicone baking mats.  If desired, place a template under the parchment paper with 1 1/4 – 1/12 inch diameter circles to use as a piping guide.  (I like using these baking mats/template for piping even sized macarons.)
2. Sift together the almond flour and confectioners sugar into a large bowl, discarding any large granules remaining in the sieve.  (If there are a lot of large pieces remaining, place all of the almond flour and sugar into a food processor and grind for about a minute, then sift again.  There should be very few large granules left.)  Add in the pumpkin pie spice and whisk to combine.  Add in the first portion of egg whites (55 grams) to the bowl.  Use a rubber spatula to mix the egg whites into the dry ingredients to form a thick paste.
3. In a small saucepan, add in the granulated sugar and water.  Use a candy thermometer to measure the temperature of the mixture closely while cooking.  Begin heating on medium-high and bring the temperature to 240°F.
4. Meanwhile, while the sugar is cooking, begin whisking the second portion of egg whites (55 grams) in the bowl of a stand mixer fitted with the whisk attachment.  Whisk until the egg whites are frothy and form tight small white bubbles.  Once the sugar syrup reaches 244°F reduce the mixer to low speed and very carefully add the hot syrup into the egg whites in a slow stream along the side of the mixing bowl.  Avoid hitting the whisk when adding the syrup to prevent it from splattering around the sides of the bowl. 
5. Once all of the syrup is added increase the speed to high and whisk for 3-4 minutes, until soft peaks form.  At this point, stop the mixer and add in your gel food coloring (if using).  Continue whipping the egg whites for a few more minutes until they are thick, glossy and form stiff peaks.  The meringue should have cooled down to room temperature. 
6. Take a large spatula full of the meringue and add it into the almond-sugar paste.  Fold the meringue into the paste to begin loosening the consistency.  Add in the remaining meringue and continue folding into the batter, sweeping the spatula around the outside of the bowl and then cutting through the middle to combine.  Keep mixing until the batter falls off the spatula in a “ribbon” and moves like slow lava.  You should be able to draw a figure “8” with the batter as it falls off the spatula.  The “ribbon” should smooth itself back into the bowl of batter after about 10 seconds.  This is when the batter is ready to pipe.
7. Transfer the batter to a piping bag fitted with a medium sized round tip.  Secure the end of the piping bag with a bag clip or a rubber band to prevent the batter from spilling out of the top.  Pipe the batter onto the prepared baking sheet in even circles, about 1 1/4 – 1 1/2 inch in diameter.  Gently but firmly tap the baking sheet on your work surface a few times to release any air bubbles from the piped macarons.  Use a toothpick to pop any stubborn air bubbles. 
8. Let the piped macarons sit on the counter for 30-60 minutes to dry out and form a skin.  They should no longer feel sticky when lightly touched.
9. Preheat the oven to 325°F.  Bake one sheet at a time for 12-14 minutes.  Macarons are done when the tops are set and there is little to no jiggle from the “feet” when lightly tapped.  Let the macarons cool completely before removing from the baking sheet. 

Pumpkin Spice Ganache

1. Cook the pumpkin puree in a small saucepan over medium low heat until bubbling.  Once bubbling cook for 2 minutes before removing from the heat and setting aside.  Clean out the saucepan.
2. In the same small saucepan, heat the heavy cream until simmering.  Whisk in the sugar and cornstarch until smooth.  Bring to a boil.  Once boiling, remove from the heat and whisk in the cooked pumpkin puree and pumpkin pie spice until smooth.
3. Finely chop the white chocolate and add to a large heatproof bowl.  Pour the hot cream/pumpkin mixture over the white chocolate and let sit for 5 minutes.  Use a rubber spatula to mix until the chocolate is melted and the ganache is fully combined and smooth.  (If needed, heat the ganache in the microwave in 15 second increments until chocolate is fully melted.)
4. Add in the diced butter and mix again.  Cover with plastic wrap and place in the fridge until the ganache is set.
5. Once the ganache has firmed up, add to a piping bag fitted with a small round tip.  Pipe the pumpkin ganache into the center of one macaron shell.  Place a second macaron shell on top and gently sandwich the two together.  Repeat until all macarons are filled.  Store filled macarons in the fridge.