Combine the frozen strawberries, bananas, almond milk, ice cubes, and optional almond butter in a blender.: As you add the ingredients you will notice the cool aroma of strawberries and the sweeter scent of bananas , a contrast that tells you the flavor balance is building. Layering matters, so put liquids in first to help the blades catch, then add fruit and finally the ice cubes so they sit near the blades for efficient crushing. If you toss everything in haphazardly the blender can struggle, which is why starting with the almond milk is practical. A common mistake is overpacking the jar, which can jam the blades, so leave some headspace to allow circulation. Also, if your almond butter is very thick, spoon it in small dollops to prevent clumping. Visually you should see distinct pieces before blending, and you might hear a light grinding as the ice settles at the blade level.
Blend on high speed until the mixture is smooth and creamy.: During blending you will hear the initial crunch of ice cubes give way to a steady hum, and the mixture will darken and become uniformly colored, signaling that the strawberries and bananas have fully incorporated. The smell will shift to a more unified fruity aroma, and when you stop the blender and lift the lid the texture should be velvety with no large chunks. If you still see fruit bits or hear intermittent loud thunks, pulse a few more times and scrape the sides down, because uneven blending results in a lumpy mouthfeel. Overblending can warm the smoothie slightly from friction, which reduces the icy refreshment you want, so aim for a smooth yet cold result. If the mixture is too thick to move, add a splash more almond milk and blend briefly; too thin would taste watery, so adjust carefully.
Pour the smoothie into glasses and enjoy immediately, or store in a covered jar in the refrigerator for up to 24 hours.: When you pour, note how the smoothie flows, thick and ribbon like, which is a good texture indicator. A freshly poured glass will be cold to the touch and may have tiny air pockets on the surface that give a light velvet mouthfeel. If you plan to drink later, use an airtight jar, because exposure to air dulls the bright fruit notes and the color may oxidize, turning slightly brown. Chill in the fridge for a short period if you need to, but do not freeze after blending, because thawing changes the texture. A common error is leaving it at room temperature which hastens flavor loss and potential fermentation of the banana. When reheating or reblending later, give it a quick stir rather than high speed blending to preserve the texture. For best flavor, enjoy within 24 hours, and always give it a sniff to make sure it still smells bright and fresh before sipping.