Preheat oven to 250 degrees. Line a baking sheet with parchment paper.
Heat oil in a large dutch oven, large enough to stir in the final popcorn volume and almonds. Add the popcorn. The oil should be hot enough for the kernels to sizzle when they hit the pan.
Cover and cook over medium heat, shaking the pan until the kernels stop popping, about 3-4 minutes. Transfer popcorn to a large bowl to cool. Remove unpopped kernels.
Wipe the pot clean with a paper towel. Return pot to the stove end melt the butter over medium high heat. Add sugar and corn syrup and stir to combine.
Allow mixture to cook, without stirring, until deep amber colour, about 5 minutes. (A candy thermometer should read 325 degrees).
Remove the pot from the heat and add the salt and baking soda. Stir and it will be quite foamy. Stir in the amaretto, carefully, since it may sputter.
Immediately add popcorn and almond and stir until evenly coated.
Pour the popcorn mix out onto the lined baking sheet. Smooth it out to the edges so it is a single layer. Bake for one hour, stirring every 15 minutes to break up the clumps.
Cool completely on the baking sheet, then transfer to an airtight container. Can be stored up to a week.