Easy Raspberry Oatmeal Crumble Bars

These Raspberry Oatmeal Crumble Bars are one of those wonderfully simple collected recipes that earn a permanent spot in the recipe box. A buttery yellow cake mix and quick-cooking oat mixture forms both the base and the golden crumble topping, while raspberry jam melts into a sweet, bright, slightly tart filling in the center. The contrast between the soft jam layer, chewy oats, and crisp edges makes them taste far more indulgent than the short ingredient list suggests.

I especially like this style of bar when I need an easy dessert for a potluck, bake sale, or busy weeknight. There is no mixer, no complicated dough, and no need to make a filling from scratch. Give the pan enough time to cool before slicing; the jam firms as it cools, giving you much neater squares.

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Ingredients

1 package (18.25 oz) yellow cake mix

2 ½ cups quick-cooking oats

¾ cup margarine, melted

1 cup raspberry jam

1 tbsp water

Instructions

1. Prepare the pan. Preheat the oven to 190°C / 375°F. Lightly grease a 9-by-13-inch baking pan.
2. Make the crumble. Combine the cake mix and quick-cooking oats in a large bowl. Pour in the melted margarine and stir until no dry cake mix remains and the mixture forms moist, crumbly clusters.
3. Form the crust. Spread half of the oat mixture over the prepared pan. Press it firmly and evenly into the bottom to create the base.
4. Add the raspberry layer. Stir the raspberry jam and water together until smooth and easily spreadable. Gently spread it over the crust, leaving the pressed oat layer intact.
5. Add the topping. Scatter the remaining oat mixture evenly over the raspberry filling. Keep the topping somewhat loose rather than pressing it firmly into the jam.
6. Bake. Bake for 18 to 23 minutes, until the crumble topping is lightly golden and the filling is hot.
7. Cool and slice. Let the bars cool completely in the pan before cutting into 24 pieces. Cooling allows the raspberry layer to set and makes the bars easier to slice cleanly.

Cooking Notes

Quick-cooking oats work especially well because their smaller flakes bind readily with the cake mix and melted fat. Old-fashioned rolled oats can be substituted, but the finished crumble will be noticeably coarser and chewier.

Avoid overbaking. The topping only needs to become lightly golden; baking until deeply browned can leave the bars dry after cooling.

For clean squares, cool the pan completely before slicing. Chilling the cooled bars briefly can make especially neat cuts when preparing them for a party or bake sale.

Butter can replace the margarine in an equal amount. It will give the bars a more pronounced buttery flavor and may slightly change the estimated nutrition.

Nutrition

Yields: 24 servings

Recommended Serving Size: 1 bar, or approximately 1/24 of a 9-by-13-inch pan.

Cake mix, oats, margarine, and raspberry jam provide nearly all of the recipe’s calories. Baking removes some moisture but does not significantly reduce the energy contained in the batch. Based on the stated 24-bar yield and standard nutrition values for these ingredients, the original estimate of approximately 210 calories per serving is reasonable.

Estimated Nutrition per Serving

• Calories: 210 kcal
• Fat: 9.0 g
• Carb: 32.0 g
• Protein: 2.0 g

Nutrition is an estimate; values vary with the brands of cake mix, margarine, and raspberry jam used.

Recipe Science

These bars use a convenient crumb-crust technique in which dry cake mix and quick-cooking oats are coated with melted margarine. Half becomes a compact bottom crust, while the remainder stays loose enough to form a crumbly topping. Raspberry jam provides the concentrated fruit layer, and a small amount of water makes the preserves easier to spread without disturbing the base.

During baking, starches in the cake mix and oats absorb moisture while the fat limits excessive gluten development, helping produce a tender, crumbly texture instead of a breadlike one. The sugars in the cake mix and jam contribute sweetness and browning. A relatively short baking time is appropriate because there is no raw fruit filling requiring prolonged cooking.

The bars are practical for make-ahead preparation because the filling becomes firmer after cooling. Store them covered at room temperature for short-term serving or refrigerate them for longer storage. Different fruit preserves can generally replace raspberry jam in equal amounts.

Dietary Notes & Health Alerts: Based on the supplied nutrition information, one bar contains approximately 208 mg sodium, which is about 9% of the FDA Daily Value of 2,300 mg. Saturated fat is approximately 1 g, or 5% of the 20 g Daily Value. Neither reaches the FDA’s 20% threshold for a high amount. The supplied nutrition lists 18 g total sugar but does not specify added sugar, so an accurate comparison with the 50 g Added Sugar Daily Value cannot be made. Choosing a reduced-sugar jam can lower total sugar, although the cake mix remains a significant source of added sugar.

Why You’ll Love This Recipe

• Five Simple Ingredients: Cake mix and raspberry jam eliminate most of the measuring and prep work.
• Sweet-Tart Center: Raspberry preserves cut through the rich oat crumble with concentrated berry flavor.
• No Mixer Required: Everything can be prepared with bowls and a spoon or spatula.
• Perfect for Sharing: One 9-by-13-inch pan makes 24 small bars, making this an easy choice for parties and potlucks.
• Easy to Customize: Strawberry, blackberry, apricot, or mixed-berry preserves can take the place of raspberry.

FAQ

• Can I use butter instead of margarine? Yes. Substitute ¾ cup melted butter for the margarine. Expect a richer dairy flavor and a slightly different texture.
• Can I use old-fashioned oats? Yes, although the crumble will be heartier and chewier. Quick-cooking oats produce a more cohesive bar.
• Why are my bars falling apart? They may still be warm. Let them cool completely so the fat and jam can firm up before cutting.
• Can I make these ahead? Absolutely. Bake and cool the bars in advance, then keep them tightly covered until serving.
• Can I change the jam? Yes. Use the same quantity of another thick fruit preserve. Avoid unusually runny fruit spreads, which can make the crust soggy.

Conclusion

These easy raspberry oatmeal bars prove that a short ingredient list can still deliver a wonderfully satisfying homemade dessert. Cooking is always a little personal, so don’t hesitate to swap the preserves or adjust the recipe to make these bars your family’s own.

Which jam would you try next: strawberry, blackberry, or apricot? Happy baking, and enjoy every bite.