Orange Biscotti

• 3 drops orange extract
• 1 extra egg yolk
• 325 gr unbleached flour
• 120 ml water (cold)
• 65 gr sugar
• 34 gr butter melted (unsalted)
• 16 gr rum (light)
• 16 ml olive oil
• 12 gr orange peel (grated)
• 1 gr salt