This sounds like what you describe, and one of my favorites! I always used to ask for this for my birthday supper!
MIRACLE CHEESECAKE
1 3 oz. pkg. lemon Jello
1 c. boiling water
1 8 oz. pkg. cream cheese
1 c. sugar
3 T. lemon juice
1 tsp. vanilla
1 can evaporated milk, well chilled
3 c. graham cracker crumbs
1/2 c. butter,melted
1/3 c. sugar
Combine cracker crumbs, butter and 1/3 c. sugar. Reserve 1/3 c. crumnbs and press remainder into a 9x13 pan and chill or bake for 10 minutes at 350 degrees and cool.
Dissolve gelatin in boiling water and add lemon juice. Chill until slightly thickened. Blend together cream cheese, 1 c. sugar and vanilla until creamy. Add partially set jello mixture and mix until well blended. Pour chilled evaporated milk into mixer bowl and beat until whipped and fluffy. Fold into gelatin mixture and pour into graham cracker crust. Sprinkle with remaiing crumbs and chill for at least two hours before serving.
I think you could substitute flavors of jello and experiment with this a little if it is not exactly as you remember it. I think it would be good with orange-pineapple jello and add some crushed pineapple, too.