Preheat a small skillet over medium-low heat. In a small bowl, combine 0.25 cup flour, 0.25 cup rolled oats, 1 tbsp brown sugar and a pinch (0.25 tsp) salt. Add the 2 tsp cold cubed butter and use a fork or your fingertips to cut the butter into the dry ingredients until the mixture resembles coarse crumbs.

Toast crumble

Transfer the crumb mixture to the preheated skillet. Toast, stirring frequently, for 3–5 minutes until the oats are lightly golden and the mixture smells nutty. Remove from heat and let cool on a plate—this will crisp up as it cools.

Smoothie Base

Prepare fruit

If using whole berries, measure 1 cup frozen mixed berries. Slice the banana and measure 1/2 cup (about half a medium banana). If berries are large, break them into smaller pieces so they blend evenly.

Blend

In a blender combine 1 cup Greek yogurt, 1 cup frozen mixed berries, 0.5 cup banana, 0.5 cup unsweetened almond milk and 4 ice cubes. Secure lid and blend on high until smooth and creamy, about 45–60 seconds. Stop and scrape down sides once if needed.

Sour & Sweet Balance

Adjust flavor

With the blender running on low, add 2 tbsp fresh lemon juice, 1 tsp apple cider vinegar, 1 tbsp honey (or agave), and 0.5 tsp lemon zest. Blend for an additional 10–15 seconds to incorporate. Taste and adjust: add up to 1 tbsp more honey if you prefer sweeter, or up to 1 tsp more lemon juice for brighter sourness.

Serve & Garnish

Pour the smoothie into a chilled tall glass (about 12–16 oz). Spoon 1–2 tablespoons of the cooled pastry crumble over the top if using.

Garnish with 4 fresh mint leaves, a thin lemon wheel on the rim and skewer one extra frozen berry if desired. Serve immediately with a straw and small spoon for the crumble.