1 Heat 1 Cup Of The Cream, 1 Cup Of Milk, Sugar, And A Pinch Of Salt In A Medium Saucepan On Medium Heat Until Steaming, But Not Boiling. Stir In The Instant Coffee Until It Is Dissolved. 2 Pour The Remaining 1 Cup Of Cream Into A Medium Size Metal Bowl, Set In An Ice Water Bath In A Larger Bowl. Set A Mesh Seive On Top Of The Bowls. Set Aside. 3 In A Separate Bowl, Whisk The Egg Yolks Together. Slowly Pour The Heated Milk, Cream, Coffee Mixture Into The Egg Yolks, Whisking Constantly So That The Egg Yolks Are Tempered By The Warm Milk, But Not Cooked By It. Pour The Warmed Egg Yolks Back Into The Saucepan. 4 Stir The Mixture Constantly Over Medium Heat With A Heatproof, Flat-Bottomed Spatula, Scraping The Bottom As You Stir, Until The Mixture Thickens And Coats The Spatula So That You Can Run Your Finger Across The Coating And Have The Coating Not Run. Be Patient. This Step Can Take 5 To 10 Minutes. 5 Pour The Custard Through The Seive And Stir It Into The Chilled Cream. Chill Mixture Thoroughly In The Refrigerator. 6 When Thoroughly Chilled And Ready To Put Into Your Ice Cream Maker, Add The Rum And The Crushed Oreo Cookies. Process The Mixture In Your Ice Cream Maker According To The Ice Cream Maker Directions. Transfer Mixture To A Plastic Storage Container And Freezer In Your Freezer Until Firm, At Least 6 Hours.