Prep your pan: Line an 8x8-inch pan with parchment, leaving overhang on two sides for easy lifting. For thicker fudge, use a smaller pan.

Warm the base: In a small saucepan over low heat, add 1 cup creamy natural peanut butter and 1/2 cup unsalted butter. Stir until smooth and fully melted. Keep the heat low to avoid scorching.

Sweeten and flavor: Whisk in 1/2 to 3/4 cup powdered erythritol or allulose, 2–3 tablespoons heavy cream, 1 teaspoon vanilla extract, and a pinch of salt. Adjust sweetener to taste. If using allulose, note it’s slightly less sweet than erythritol blends.

Smooth it out: Continue whisking over low heat for 1–2 minutes until glossy and uniform. If it looks oily, take it off the heat and whisk vigorously to emulsify. A quick blitz with an immersion blender can help.

Add extras: Fold in any add-ins like 1/4 cup chopped peanuts or a handful of sugar-free chocolate chips.

Pour and level: Spread the mixture into the lined pan. Tap the pan gently on the counter to release air bubbles and smooth the top.

Optional chocolate layer: Melt 1/2 cup sugar-free chocolate chips with 1 teaspoon coconut oil. Pour over the peanut layer and spread thinly.

Chill to set: Refrigerate for 1–2 hours, or freeze for 25–30 minutes, until firm but sliceable.

Slice and store: Lift out using the parchment and cut into 16–25 squares. For clean cuts, warm a knife under hot water, wipe it dry, and slice.