Pour 1 cup raw cashews into a bowl and cover with hot water. Let soak for 30 minutes.

Drain and rinse the soaked cashews under cool running water.

Add drained cashews and 1 cup unsweetened almond milk to a high-speed blender. Blend on high for 60 to 90 seconds until smooth.

Strain the cashew mixture through a fine mesh strainer into a large mixing bowl, pressing with a spoon to extract all liquid.

Pour 1 can (13.5 oz) full-fat coconut milk into the bowl and whisk until uniform.

In a separate bowl, whisk 6 egg yolks with 1/4 cup maple syrup until pale and slightly thickened, about 2 to 3 minutes.

Slowly pour the egg mixture into the cashew-coconut base while whisking constantly to temper the eggs.

Whisk in 1 teaspoon vanilla extract, 1/2 teaspoon ground nutmeg, 1/4 teaspoon ground cinnamon, and a pinch of sea salt.

Transfer the eggnog to a glass pitcher and refrigerate for at least 2 hours or overnight for best flavor.

Stir gently before serving, garnish with additional nutmeg, and optionally spike with 1/2 cup rum or brandy.