Preparation of the Oven: Initiate by preheating your oven to a temperature of 350 degrees Fahrenheit.
Combining Ingredients: Employ an electric mixer set on a low setting to meticulously combine the butter, flour, sugar, and egg. The mixture should attain a crumbly consistency. It is imperative to reserve one and one-half cups of this mixture for later use as a topping.
Formation of the Base: Carefully press the remaining mixture into a 13 x 9 inch baking dish, previously prepared. Ensure the formation of a uniform and even base.
Application of Jam: Proceed to evenly spread the entire jar of seedless raspberry jam atop the prepared crust, ensuring a consistent layer.
Adding the Topping: Gently crumble the previously reserved topping over the jam layer, and lightly press it to adhere.
Baking Process: Place the baking dish in the preheated oven and bake for a duration of 30 to 40 minutes, or until the surface attains a golden brown hue.
Finalization: Once baked, allow the bars to cool completely prior to cutting. This will ensure neat and clean slices. Serve and enjoy.