Melt 1 tablespoon of butter in a medium non-stick skillet over medium-high heat. Add the squash and sauté until lighter in color and soft, but not turning too much, about 5 minutes. Remove from the heat and cool.: The smell at this stage is rich and slightly nutty as the butter liquefies, and you want to see it shimmer but not smoke. The surface should glisten and move around the pan when you tilt it, signaling even heat. This step heats the pan so the butter can help start the cooking of the shredded butternut squash , promoting early caramelization. If the butter browns too quickly, the heat is too high, which will impart a bitter taste, so lower the flame at once. A common mistake here is rushing to add the squash while the butter is still foaming hard, which leads to uneven cooking and potential splatter.
In a medium mixing bowl, stir together the squash and egg. Add the remaining ingredients and stir to combine.: As the butternut squash hits the pan you should hear a gentle hiss, not a loud splatter. Within a minute the strands will begin to loosen, and by two to three minutes they will release steam and soften. The visual cue to stop sautéing is when the strands look slightly translucent and have lost raw brightness, but they should not collapse into mush. This partial cooking helps evaporate excess moisture so the latkes crisp instead of becoming soggy. If you leave the squash in the pan too long it will break down and yield a dense cake rather than a light interior, so aim for tenderness with structure.
Coat a large cast iron skillet with a generous layer of olive or canola oil, and set it over high heat. Test the heat with the first latke: add a tablespoon full of batter to the pan. The latke should immediately sizzle and firm. Cook for one minute on each side. Remove to a plate with paper towels. Repeat with the remaining batter, making sure not to crowd the pan.: Cooling the cooked butternut squash makes it easier to combine with the egg and flour without scrambling the egg or creating a runny batter. You will notice steam fade and the squash firm slightly as it cools. This pause also prevents the batter from thinning, which would cause the latkes to spread too much during frying. If you skip cooling, you risk a loose mixture that does not hold shape, making the cakes fall apart in the pan.
In the meantime, combine the yogurt and the cumin. Salt to taste.: When you fold the warm but not hot butternut squash into the beaten egg , the mixture becomes cohesive and slightly glossy. The egg binds the strands and starts to develop the structure you will feel when shaping the latkes. The texture should be moist but manageable rather than watery. If it feels wet, let it sit a few minutes to allow residual steam to dissipate, because excess moisture will prevent crisping during frying.
To serve, dollop each latke with a little yogurt, and garnish with a cilantro leaf.: As you fold in the flour , sugar , salt , cumin , and cilantro , you will see the batter come together into a cohesive mixture that holds shape when scooped. The flour absorbs stray moisture while the seasoning flavors bloom into the warm squash. If the batter appears too loose, a little more flour will help, but be careful not to overdo it because that will dull the squash. Conversely, if it becomes dry, a dash of water or a small amount of extra egg can revive it.
Serve immediately, or cover and refrigerate. Simply reheat the cakes in a 400 degree oven for 5-10 minutes until crisp.: When the oil is hot it will shimmer and move easily across the skillet surface, and a drop of batter should sizzle immediately. The high heat is essential to form a crisp crust quickly, sealing the edges so the interior steams to tenderness without absorbing excess oil. Use an oil with a high smoke point like canola or refined olive to avoid burnt flavors. A common error is using too little oil which prevents even browning and leads to sticking.
Test the heat with the first latke add a tablespoon full of batter to the pan: The first test cake tells you everything. If it immediately sizzles and firms up at the edges, the oil is ready. Watch for a deepening golden color at the rim within about a minute as that indicates the Maillard reaction is underway. If the test piece browns too quickly, lower the heat; if it sinks and absorbs oil, raise the temperature slightly and allow the skillet to recover. This trial prevents ruining the entire batch.
The latke should immediately sizzle and firm cook for one minute on each side: During this short cook you will hear a satisfying crackle and see the edges tighten and become crisp, transforming from pale to golden. The quick flip keeps the interior tender while giving the exterior a pleasant crunch. Press gently with a spatula to check firmness; a properly cooked latke will release easily from the pan. The main pitfall here is flipping too early which splatters batter and causes tearing, so wait until it lifts cleanly before turning.
Remove to a plate with paper towels repeat with the remaining batter making sure not to crowd the pan: As you transfer finished latkes to the towel lined plate, they will continue to crisp slightly from residual heat. Giving each cake breathing room in the pan ensures the oil temperature recovers between batches and prevents steaming. If you crowd the skillet, the cakes will steam and stay limp rather than crisp. Also, change or refresh the oil if it becomes darkened to avoid imparting bitter flavors.
In the meantime combine the yogurt and the cumin salt to taste: Stirring the Greek yogurt with the second measure of cumin creates a cooling, aromatic sauce with a soft earthiness that echoes the latke seasoning. Taste and adjust with salt to balance the tang. The creamy texture of the Greek yogurt contrasts the fried surface, giving each bite a bright finish. If your yogurt is too thin the sauce will run off the cakes instead of clinging, so strain if necessary.
To serve dollop each latke with a little yogurt and garnish with a cilantro leaf: The sight of bright white Greek yogurt atop golden cakes with a fleck of green cilantro is inviting and texturally complementary. Spoon a small amount so the first bite contains both elements. Serving straight from the pan keeps the exterior crisp while the yogurt adds coolness. A mistake is over topping which overwhelms the crispy experience.
Serve immediately or cover and refrigerate simply reheat the cakes in a 400 degree oven for 5 to 10 minutes until crisp: When you reheat, the oven revives the crust and warms the center without making them greasy, restoring that just fried texture. The sound of the edges crisping as they come back to life is reassuring. If you microwave instead, expect a softer result. Reheating too long can dry them out, so check at the shorter end of the range.