Prep your gear: Line a small loaf pan or bar molds with parchment. Have a whisk or silicone spatula ready. Sift the powdered sugar and milk powder to remove lumps.

Set up a double boiler: Bring an inch of water to a gentle simmer in a saucepan. Place a heatproof bowl on top, making sure it doesn’t touch the water.

Melt the cocoa butter: Add cocoa butter to the bowl. Heat gently, stirring, until fully melted and clear. Keep the temperature under 130°F (54°C) to protect the flavor.

Whisk in the dry ingredients: Remove from heat. Add powdered sugar, milk powder, salt, and vanilla. Whisk until smooth. If it thickens, put it back over the warm water briefly.

Strain for ultra-smooth texture (optional): Pass the mixture through a fine mesh sieve into a clean bowl to catch any tiny lumps.

Quick temper for shine (recommended): Cool the mixture to about 80–82°F (27–28°C), stirring continuously. Then rewarm gently to 84–86°F (29–30°C). This encourages stable cocoa butter crystals for a glossy finish and clean snap.

Add mix-ins: Stir in any extras now so they distribute evenly.

Pour and set: Pour into your lined pan or molds. Tap lightly to release air bubbles. Smooth the top with a spatula.

Chill briefly: Refrigerate for 15–25 minutes, just until firm. Don’t over-chill or you may get condensation later.

Unmold and store: Pop out the bar. If you tempered, it should be glossy and firm at room temperature.