Combine cream and milk in a medium saucepan, and bring the mixture just to gentle boil over medium heat. Meanwhile, in a mixing bowl, with an electric hand mixer on medium speed, whip together egg yolks and sugar until very smooth and light in color about 1 minute. Once cream mixture has reached a low boil reduce heat to medium low. Measure out 1/2 cup hot cream mixture.
With the mixer on low speed, slowly pour the 1/2 cup hot cream mixture into egg yolk mixture. Once thoroughly combined, pour egg/cream mixture into saucepan with hot cream/milk mixture and stir to combine. Cook over medium low heat, stirring constantly until mixture coats the back of a wooden spoon, about 3 -4 minutes. Remove from heat, stir in raspberry jam, raspberry extract, vanilla extract and optional food coloring.
Pour mixture into a bowl, cover with plastic wrap, pressing plastic wrap directly against the surface of the custard to prevent a skin from forming. Cool completely in the refrigerator. Once completely chilled transfer bowl to freezer and freeze mixture 1 hour. Pour lightly frozen mixture into an ice cream maker and process according to manufacturer directions. Pour custard into an airtight container and freeze 1 -2 hours until slightly firm (the frozen custard I'm used to is similar to soft serve but thicker).