Combine the butter, heavy cream, confectioners sweetener, liquid allulose, and salt in a small saucepan set over low heat. Warm the mixture gently without allowing it to reach a boil.

Whisk the egg yolks in a separate heatproof bowl until they appear smooth and pale in color. Slowly whisk several spoonfuls of the warm cream mixture into the yolks to temper them before pouring the tempered egg mixture back into the saucepan.

Stir the custard continuously over low heat until the liquid thickens and holds a clear line across the back of a spoon at 175 °F. Transfer the thickened custard into a clean bowl and refrigerate for 30 minutes to cool.

Take the cooled custard from the refrigerator and whisk in the maple extract, sugar-free maple syrup, and MCT oil. Ensure the flavorings and oil are fully emulsified into the chilled base.

Pour the prepared base into your ice cream maker according to the manufacturer guidelines, fold in the toasted pecans near the end of churning, and transfer the soft cream to a 9 by 5-inch loaf pan to freeze for 2 to 3 hours for soft serve. The ice cream is ready when it reaches a smooth, spreadable consistency that scoops cleanly.