Banana Poppy Seed Cake with Lemon Buttercream

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Banana Poppy Seed Cake with Lemon Buttercream ~ snack time just got a whole lot more interesting with this unique combination of bananas, poppy seeds, and lemon ~ you can whip up this easy one bowl cake in no time.

Banana Poppy Seed Cake with Lemon Buttercream, sliced on parchment paper

Bake up this banana poppy seed cake when a good friend’s coming over for coffee, or there’s a last minute potluck at the office, or maybe you’ve been so good about eating super healthy for a couple of weeks now that you could use a treat.  Whatever the excuse, I think you’ll be glad you gave it a shot.  If you’re going to share it, be sure to have copies of the recipe ready to go, you’re gonna get asked.

A piece of Banana Poppy Seed Cake with fork on a wooden table

This is a classic dense and moist banana cake with the footprint of a blondie ~ kicked up a notch or two with lots of crunchy poppy seeds and a tangy lemon frosting.  Why should lemon and almond get all the fun when it comes to poppy seeds?

I don’t know why I haven’t thought to combine all these elements together before, they make for a cake that’s unusual but familiar at the same time.

Banana Poppy Seed Cake with lemon buttercream frosting

I’m generous with this particular frosting, which has a similar tangy quality to a cream cheese frosting, but it’s even easier to whip up.  You might know it from my BLUEBERRY ZUCCHINI CAKE WITH LEMON BUTTERCREAM.  It’s butter-heavy, and because of that I think it tastes best chilled, so I keep my cake in the refrigerator until I’m ready to eat.

Banana Poppy Seed Cake batter

No need to haul out the heavy equipment for this banana snack cake ~ just a whisk and a bowl will do fine.

Banana Poppy Seed Cake with poppy seeds

It’s no secret that I love poppy seeds ~ I use them all the time, in everything from LEMON POPPY SEED PANCAKES to CHICKEN SALAD WITH POPPY SEED MAYONNAISE.  They just add that special touch to so many foods.  I buy them in bulk, which means I always have some on hand to add to my recipes.

Ingredient spotlight: BULK POPPY SEEDS


If your local store doesn’t carry them, you can find poppy seeds in bulk, online, HERE. To store extra poppy seeds, put them in an airtight container in the refrigerator (6 mos) or freeze them, (1 year).


Reader Rave ~

“Absolutely amazing. I now have to gift the rest of it so I won’t eat anymore. I did use zest in the frosting. It was perfect.”  ~ Leia

Banana Poppy Seed Cake with Lemon Buttercream
Rate this recipe
9 ratings

Yield: serves 9-12

Banana Poppy Seed Cake with Lemon Buttercream


  • 2 Tbsp unsalted butter, at room temperature
  • 2/3 cup sugar
  • 1/2 cup sour cream
  • 1 large egg, room temperature
  • 2-3 ripe bananas, mashed (to make about 3/4 cup mashed)
  • 1/3 cup poppy seeds
  • 1 tsp vanilla extract
  • 1 cup flour
  • 1/4 teaspoon salt
  • 1/2 teaspoon baking soda
    lemon buttercream
  • 8 Tbsp (1 stick, 1/2 cup) unsalted butter, at room temperature
  • 2 cups confectioner's sugar
  • juice of 1 lemon (about 2 Tbsp)
  • the tiniest drop of yellow food coloring (optional)


  1. Set oven to 350F Lightly spray a 9x9 square baking pan. I like to line it with parchment paper so I can lift the cake out after baking for easy frosting and cutting.
  2. Cream the butter, sugar, and sour cream together until light and fluffy. Beat in the egg, mashed banana, poppy seeds, and vanilla.
  3. Whisk the flour, salt, and baking soda together and add to the wet ingredients. Mix until just blended.
  4. Turn the batter out into the pan and smooth out evenly. Bake for about 35 minutes, or until the top is just turning golden and the middle is set. A toothpick inserted in the center should be free of wet batter.
  5. Let cool on a rack completely before frosting.
  6. Make the frosting by beating the butter and sugar together with the lemon juice and food coloring, if using. Add a touch more juice if the frosting is too thick, or a little more sugar if too thin.
  7. I like to store the cake in the refrigerator, and it will keep for up to a week.

Make it your own ~

  • Add the zest of the lemon to the frosting if you like.
  • Substitute chopped walnuts for the poppy seeds.
  • Substitute cream cheese for the butter in the frosting.


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  • Reply
    August 27, 2018 at 5:54 pm

    Hi Sue,
    Do you think this recipe would work in muffin form instead of a cake?
    Thanks in advance!

    • Reply
      August 27, 2018 at 6:06 pm

      I’m sure you could bake it that way Cecily, just be aware that it would be a dense type of muffin, not fluffy. The cake is sort of blondie-like in texture.

  • Reply
    June 5, 2018 at 5:25 am

    Hi, just wondering what kind of flour should be used for this; plain or self-raising flour?

    • Reply
      June 5, 2018 at 6:55 am

      I use plain all purpose flour, Verity.

  • Reply
    Banana Poppyseed Cake | Real Mom Kitchen
    May 17, 2018 at 3:42 pm

    […] 3.5.3240 Recipe adapted from The View from Great Island. […]

  • Reply
    May 10, 2018 at 2:15 pm

    Lovely recipe thank you . I used ground almonds instead of flour and it was very moist and light.

    • Reply
      May 10, 2018 at 2:38 pm

      Thanks Eugene, that’s great to know about the gf option!

  • Reply
    April 1, 2018 at 5:57 pm

    I made this to have for Easter morning breakfast since I wanted something special but we didn’t have much time before rushing off to church. I knew the frosting and bananas would add sweetness, so I halved the sugar. I don’t typically buy sour cream, but always have whole milk yogurt on hand, so that’s what I subbed. Poppy seeds, 1/4c. I replied to someone else that, yes, using gluten-free flour works nicely. The only other change was to use some of the frosting the I already made for a carrot cake, which was a maple cream cheese frosting. We all loved it! Such a nice variation of a banana bread. Adding this to my favorites!

    • Reply
      April 2, 2018 at 7:03 am

      Thanks for the feedback, Karla, and I’m glad to know that the yogurt worked well. I LOVE the sound of that maple cream cheese frosting, I’m definitely going to steal that idea from you ;)

  • Reply
    March 15, 2018 at 4:03 am

    Absolutely amazing. I now have to gift the rest of it so I won’t eat anymore. I did use zest in the frosting. It was perfect.

  • Reply
    March 10, 2018 at 7:12 pm

    Can I use prepared poppy seeds in a tin or do you use dry ?
    Looks so good

    • Reply
      March 10, 2018 at 7:17 pm

      I used dry, Lou, but I wonder if you might be able to use the prepared seeds in place of the dry mixed with the cream. I don’t imagine it would taste quite as good, because the canned stuff has mostly added sugar.

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