1. Preheat oven to 350 degrees Fahrenheit. Cream margarine and sugar until light and ﬂuffy. Beat in eggs and vanilla until combined.
2. Spread 3/4’s of batter evenly in 10×15-inch baking pan. Spread jam over dough; sprinkle with walnuts.
3. Mix remaining dough with 1/4 cup remaining ﬂour and crumble on top of jam. Bake for 35 minutes. Cool and cut into squares or bars.
4. Mix in three and a half cups of ﬂour and the salt, gradually, until thick batter is formed.