Sourdough Olive Oil Birthday Cake

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By Kristen on October 26, 2025

This sourdough olive oil cake is the perfect cake for a birthday or special occasion, or even for dessert during tea time with your children.

This moist cake has become one of our family’s favorite cakes to bake for birthday celebrations. Three of our daughters asked for it on their birthdays this year. 

Add some homegrown flowers for the perfect aesthetics! I grew the nasturtiums on this cake specifically for our younger daughter’s fourth birthday. 

Edible homegrown flower and herb options to add to your cake or other recipes you use:

• Chamomile
• Nasturtium
• Pansy
• Borage
• Calendula 
• Rose
• Lavender
• Mint
• Lemon balm
• Thyme
• Rosemary

What You’ll Need

Cake:

• 2 cups flour (organic, unbleached all-purpose or flour of choice) 
• 1/2 cup coconut milk 
• 2 fresh eggs
• 1/2 cup sourdough discard 
• 1/2 cup organic olive oil 
• 3/4 cup sugar
• 1 teaspoon sea salt 
• 1/2 teaspoon baking soda
• 2 teaspoons baking powder

Optional Ingredients:

• 1 teaspoon vanilla extract
• citrus zest of choice (orange or lemon zest) 
• 2 tablespoons of citrus juice (orange or lemon juice)

Buttercream Icing:

• 4 1/2 cups of sifted powdered sugar
• 1 tablespoon vanilla extract
• 2 sticks room temperature butter
• 2-3 tablespoons heavy cream
• 1/2 teaspoon salt

SUBSTITUTES 

• Olive Oil – can be substituted with coconut oil, although this will change the taste 
• Organic All-Purpose Flour – Flour of choice
• Coconut Milk – Organic whole milk, raw milk, or milk of choice

EQUIPMENT NEEDED

• Medium & large mixing bowl with a whisk or stand mixer with paddle attachment 
• cake pans (round 9″ cake pan)

INSTRUCTIONS

• Preheat your oven to 350 degrees. 
• In a medium mixing bowl, whisk together your dry ingredients (flour, salt, baking powder, baking soda)
• In a separate, larger mixing bowl or stand mixer, cream together coconut milk, eggs, sourdough starter, olive oil, and sugar. 
• Add your dry ingredients to your olive oil mixture and combine well.

• Pour batter into an oiled cake pan. I prefer to butter and oil my dish.
• Bake at 350 for 45-50 minutes. (Prep icing while your cake is baking – see instructions below)

• Once slightly cooled, gently remove from your cake pan to finish cooling on a wire rack or cooling rack.
• Once your cake has completely cooled, move your cake to your cake stand and apply your icing with a piping bag. If you would like a completely flat top to your cake before icing, gently shave the top or center off with a sharp knife and even out your cake top. Apply your icing thickly on the top to keep any cake from breaking off into your icing.

Instructions for Buttercream Icing:

• Cream room temperature butter in a stand mixer with a paddle attachment
• Mix in salt and slowly add 4 1/2 cups sifted powdered sugar until well combined, scraping down sides with a spatula 
• Continuing to use your paddle attachment, add heavy cream and vanilla extract. 
• Once well combined, add your icing to your piping bag and apply it to your cake as desired.
• Add flowers, fruit, or lightly zest an orange or lemon over the icing. 

Store in an airtight container or a cake dish with a cake cover.

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