Use einkorn and spelt flour for tender, flavorful crumb or all-purpose flour as substitution (may need liquid adjustments)., Sourdough discard provides tangy flavor; substitute 1/4 cup plain yogurt plus 1/4 tsp active dry yeast if needed., Milk types: dairy or mild plant-based (almond, oat, soy); avoid strong-flavored like coconut., Cream cheese filling substitutes: mascarpone or ricotta-cream cheese blend (well drained and smooth)., Lemon juice can be swapped with lime or orange juice; vanilla extract can be replaced with almond extract (use half amount)., For sticky dough, refrain from adding too much flour to avoid dense kolaches; lightly flour hands and surface instead., Let dough rise fully; patience is key for sourdough dough., Press a deep well in dough balls to keep filling from oozing during baking.