Butter + Jam Crumble Cookies

Ingredients

• 1/2 cup butter, softened
• 1/4 cup packed brown sugar
• 2 Tbsp icing sugar
• 1 large egg yolk (optional)
• 1/2 tsp vanilla
• 1 cup all-purpose flour
• 1/4 tsp salt
• 1/2 cup jam or other preserves
• 1/4 cup brown sugar
• 1/4 cup all-purpose flour
• 1/4 cup oats
• 1/4 cup walnuts or pecans (optional)
• 1/4 cup coconut (optional)
• 2-3 Tbsp butter (you can eyeball this)
• pinch salt