In a small saucepan, whisk together 3/4 cup water, 3/4 cup allulose, and 2 tablespoons erythritol. Heat over medium, stirring until the sweeteners dissolve and the mixture starts to steam.

Reduce the heat to low. Sprinkle in 1/8 teaspoon xanthan gum slowly while whisking constantly to prevent clumps. Keep whisking until fully dispersed and slightly thickened, about 1 minute.

Let the syrup gently simmer for 2 to 3 minutes, stirring often. It should look glossy and lightly coat the back of a spoon. If it’s too thin, simmer another minute; if too thick, whisk in a tablespoon of water.

Remove from heat. Stir in 1 teaspoon maple extract, 1/2 teaspoon vanilla, a pinch of salt, and 1 tablespoon butter if using. Taste and adjust with a few drops of liquid stevia if you want it sweeter.

Let the syrup cool for 10 to 15 minutes. It will thicken more as it cools. Pour into a clean glass jar or bottle.

Serve warm over keto pancakes, waffles, or French toast. Stir before each use to keep the texture even.