Preheat your oven to 350F.
Make simple syrup by stirring together warm water and sugar until sugar is dissolved.
Cut the crusts off each slice of bread, then flatten them using a rolling pin. With a 3-4” flower cookie cutter, cut flower shapes out of each bread slice.
Using a pastry brush, brush simple syrup onto the tops of the bread flowers.
Tuck each flower into a mini muffin tin, alternating cups so the flowers do not touch. Press them down into the bottom of each cup and fold the petals over the top.
Bake for 5-6 minutes or until lightly toasted. Gently remove the tartlets and let cool for a few minutes on a wire rack.
While tartlets are baking, prepare mascarpone filling. Whip together heavy whipping cream, powdered sugar, and vanilla extract, until peaks form. Add the mascarpone and beat together until light and fluffy.
Optionally, you can add 1 drop of lavender oil to some or all of the mascarpone filling at this step for more of a floral flavor profile (other than just the garnishes).
Using a piping bag (or plastic bag with the tip cut off), pipe the mascarpone filling into the center of each flower tartlet cup.
Dust with powdered sugar and decorate with edible flowers and greens of your choice.
Some options include: fresh edible pansies, orchids, nasturtium, hibiscus, or lavender; dried petals (such as those found in loose leaf herbal tea); and fresh herbs such as mint, sage, tarragon, rosemary, fennel fronds, or microgreens.