In a large heavy saucepan, whisk egg yolks and brown sugar until blended; stir in heavy cream. Cook over low heat until mixture is just thick enough to coat a metal spoon and a thermometer reads at least 160°, stirring constantly. Do not allow to boil. Remove from heat immediately., Quickly transfer to a large bowl; place bowl in a pan of ice water. Stir gently and occasionally for 2 minutes. Stir in half-and-half, pumpkin, pie spice, vanilla and salt. Press plastic wrap onto surface of custard. Refrigerate several hours or overnight., Fill cylinder of ice cream maker no more than two-thirds full; freeze according to manufacturer’s directions. (Refrigerate any remaining mixture until ready to freeze.) Transfer ice cream to freezer containers, allowing headspace for expansion. Freeze until firm, 2-4 hours. , For caramel sauce, in a large heavy saucepan, spread sugar; cook, without stirring, over medium-low heat until it begins to melt. Gently drag melted sugar to center of pan so sugar melts evenly. Cook, without stirring, until melted sugar turns a medium-dark amber, 5-10 minutes. Immediately remove from heat, then slowly stir in cream, butter, salt and almond extract. Serve with ice cream. Refrigerate leftover sauce; keep leftover ice cream frozen.