Grandma’s Oatmeal Raisin Cookie Bars – Frosted Soft & Chewy Treat

There’s something incredibly comforting about the scent of oatmeal, cinnamon, and vanilla baking in the oven — it’s the kind of aroma that instantly brings you back to Grandma’s kitchen. These Grandma’s Oatmeal Raisin Cookie Bars capture all that home-baked nostalgia in one delicious bite.

Thick, chewy, and perfectly spiced, these cookie bars are like your favorite oatmeal raisin cookies but in soft, frosted square form. The buttery maple-cinnamon frosting on top adds a luscious sweetness that melts right into every bite. Perfect for potlucks, holidays, or an afternoon treat with coffee, these bars are proof that simple ingredients can create something truly special.

Why You’ll Love These

Old-fashioned flavor: A true classic with cozy cinnamon, oats, and raisins.

Soft & chewy texture: Perfectly balanced between hearty oats and tender cookie.

Frosting that’s unforgettable: Maple-cinnamon buttercream that elevates the whole dessert.

Perfect for sharing: Slice into neat bars — ideal for gatherings and bake sales.

Make-ahead friendly: Tastes even better the next day as the flavors meld together.

Ingredients

For the Cookie Bars:

• 1 ½ cups all-purpose flour
• 1 teaspoon baking soda
• ¾ teaspoon ground cinnamon
• ½ teaspoon fine salt
• ¾ cup unsalted butter, room temperature
• ¾ cup packed light brown sugar
• 2 large eggs, room temperature
• 2 teaspoons vanilla extract
• 2 cups quick-cooking oats
• 1 cup raisins

For the Frosting:

• ½ cup unsalted butter, room temperature
• 1 ½ cups powdered sugar
• 1 tablespoon maple syrup
• 1–2 tablespoons heavy cream, room temperature
• ½ teaspoon ground cinnamon
• ¼ teaspoon maple extract (optional)

Instructions

1. Preheat oven to 350°F (175°C). Grease a 9×13-inch baking pan and line it with parchment paper for easy removal.
2. Mix dry ingredients: In a bowl, whisk together flour, baking soda, cinnamon, and salt. Set aside.
3. Cream butter and sugar: In a large mixing bowl, beat butter and brown sugar together until light and fluffy (about 2 minutes).
4. Add wet ingredients: Mix in eggs and vanilla extract until smooth.
5. Combine: Gradually add the dry mixture to the wet ingredients, stirring just until combined.
6. Fold in oats and raisins. Mix until evenly distributed but do not overmix.
7. Bake: Spread batter evenly in the prepared pan. Bake for 20–25 minutes, or until golden brown around the edges.
8. Cool completely before frosting.

To Make the Frosting:

1. Beat butter until creamy.
2. Add powdered sugar gradually, followed by maple syrup, cinnamon, and maple extract if using.
3. Add cream as needed for a smooth, spreadable consistency.
4. Spread evenly over cooled bars and garnish with extra raisins if desired.
5. Slice into squares and serve.

Storage & Freezing Instructions

• Refrigerator: Store frosted bars in an airtight container for up to 5 days.
• Freezer: Freeze unfrosted bars for up to 3 months. Thaw overnight in the fridge, then frost before serving.

Serving Suggestions & Pairings

• Enjoy with a warm cup of tea, coffee, or chai for a cozy afternoon treat.
• Pair with vanilla ice cream or whipped cream for a dessert-worthy presentation.
• Sprinkle a pinch of extra cinnamon on top of the frosting for a bakery-style finish.

Pro Tips for Perfect Cookie Bars

• Use room temperature butter and eggs for smooth blending.
• Soak your raisins in warm water for 5–10 minutes to make them extra plump and juicy.
• Don’t overbake: Remove from oven when the edges are just set and the center looks slightly soft.
• Cool completely before frosting to prevent melting and sliding.
• Add a crunch: Mix in chopped pecans or walnuts for extra texture.

Conclusion

These Grandma’s Oatmeal Raisin Cookie Bars are the kind of dessert that never goes out of style. Soft, chewy, and full of nostalgic flavor, each bite is a sweet reminder of simpler times and homemade goodness. Whether for holidays, potlucks, or just a comforting treat at home, they’ll quickly become a family favorite — just like Grandma used to make.

Frequently Asked Questions

Can I use old-fashioned oats instead of quick oats?
Yes, though the texture will be slightly heartier and chewier.

Can I skip the frosting?
Absolutely. The bars are delicious on their own but the frosting makes them extra special.

Can I add nuts or chocolate chips?
Definitely — chopped pecans, walnuts, or white chocolate chips work beautifully.

Do they need to be refrigerated?
Not necessarily, but they’ll stay fresher longer when stored in the fridge.

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