- Preheat the oven to 350°F.
- In a large bowl, beat the eggs and sugar together for 3 – 4 minutes, forming a ribbon.
- Beat in the sour cream and milk.
- Stir in the raisins, walnuts, citron, zest, and nutmeg.
- Pour mixture into the pie shell, spreading it smoothly.
- Bake for 35 – 40 minutes.
- Filling should be golden brown, and knife inserted in center should come out clean.
- Cool tart.
- Meanwhile, make the sour cream sauce.
- Beat the sour cream in a bowl until smooth.
- Beat in the egg yolks one at a time, then add the sugar gradually.
- Beat in the liqueur.
- Taste for sweetness.
- Refrigerate until ready to use.