Preheat the oven to 350ºF. Prepare your doughnut pans by greasing them and then placing them on a baking sheet.
Melt the butter with with almond milk over medium–high heat in a small saucepan.
Pour this mixture over the granulated sugar in a medium bowl. Let cool until the mixture is just warm/almost room temperature, stirring every so often to help dissolve the sugar.
Add the amaretto, vanilla, vinegar, and egg and mix well to combine.
In a separate bowl, combine the flour, baking powder, and salt. Pour the wet ingredients over the dry ingredients and whisk to combine.
Transfer the doughnut batter to a piping bag and pipe into the prepared pans.
Baked the doughnuts for about 10 to 12 minutes, then transfer to a wire rack to cool completely.