In a heavy sauce pan over medium heat, bring cream and salt up to 180°F. Meanwhile, beat egg yolks with sugar until pale yellow and fluffy. Remove sauce pan from heat. Whisking constantly, add 1/2 cup of the hot cream mixture to the egg yolks. Add egg yolk mixture back into sauce pan whisking constantly.
Place sauce pan back on medium heat and whisk constantly until mixture thickens considerably, about 3 minutes. Strain mixture into bowl set in an ice bath. Stir every now and then until cooled to room temperature. Whisk in olive oil and vanilla. Refrigerate custard until chilled, preferably overnight.
Process custard based on your ice cream machine's instructions. If adding almond brittle to ice cream, add coarsely chopped brittle during last few minutes of churning.
Grease two large baking sheets. Place sugar and water in a heavy 5+ quart stock pot fitted with a candy or deep fry thermometer. Stir sugar, water and salt to evenly distribute. Over low heat, stir to dissolve sugar in water until no granules remain. Turn up heat to medium-high and bring syrup to a boil. Add butter, oil, and almonds. Continue cooking, stirring constantly until thermometer reaches 300°F. Immediately remove from heat and vigorously stir in baking soda and vanilla extract.
Pour hot brittle onto prepared baking sheets, dividing equally. With a greased spatula or two greased spoons, carefully stretch the hot brittle as thin as possible. Allow to cool completely and break in to pieces.
Makes about 1 3/4 lbs of brittle.