#Plants used for the aforementioned photograph and following observations and measurements were grown during the spring and summer in 13-cm containers in a shaded glass-covered greenhouse in Rijsenhout, The Netherlands and grown under typical Begonia production practices. During the production of the plants day and night temperatures ranged from 15° C. to 20° C. and maximum light levels were 18,000 lux. Plants were twelve weeks old when the photograph and description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2001 Edition, except where general terms of ordinary dictionary significance are used. Botanical classification: Begonia×hiemalis ‘BBDRASOPI’. Commercial classification: Elatior Begonia. Parentage: Naturally-occurring whole plant mutation of Begonia×hiemalis ‘BBDRA’, disclosed in U.S. Plant Pat. No. 19,700. Propagation: Type.—By terminal vegetative cuttings. Time to initiate roots.—About 14 days at temperatures of 20° C. Time to produce a rooted young plant.—About 20 to 35 days at temperatures of 20° C. Root description.—Medium in thickness, fibrous, white in color; plants of the new Begonia have not been observed to form tubers. Rooting habit.—Freely branching; moderately dense. Plant description: Plant form.—Compact, upright and mounded plant habit, inverted triangle; freely branching with good stem and stem base strength; flowers are fully double and abundant; moderately vigorous growth habit. Plant height.—About 20 cm to 25 cm. Plant width.—About 25 cm to 30 cm. Basal branch description.—Quantity: Freely basal branching with about five to six basal branches developing per plant. Length: About 9 cm to 13 cm. Diameter: About 1 cm to 3 cm. Texture: Smooth, glabrous. Color: Close to 138B. Leaf description.—Arrangement: Simple, alternate. Length: About 8 cm to 9 cm. Width: About 5 cm to 6 cm. Shape: Roughly deltoid. Apex: Broadly obtuse. Base: Cordate to oblique. Margin: Serrate. Texture, upper and lower surfaces: Smooth, glabrous. Venation pattern: Palmate. Color: Developing leaves, upper surface: Close to 131A. Developing leaves, lower surface: Close to 139A. Fully expanded leaves, upper and lower surfaces: Close to 131C; venation, close to 131C. Petiole length: About 4 cm to 6 cm. Petiole diameter: About 4 mm. Petiole texture, upper and lower surfaces: Smooth, glabrous. Petiole color, upper and lower surfaces: Close to 131C. Flower description: Flowering habit.—Double flowers with numerous tepals arranged in axillary cymes; typically five to six open flowers per cyme; many cymes in flower simultaneously; flowers positioned upright and outwardly above the foliar plane. Fragrance.—Not detected. Natural flowering season.—Plants will flower continuously year round in the greenhouse, however plants flower earlier and more abundantly during the summer in The Netherlands. Postproduction longevity.—Good postproduction longevity, flowers last about four weeks on the plant; flowers persistent. Cyme height.—About 6 cm to 8 cm. Cyme diameter.—About 6 cm to 7 cm. Flowers.—Shape: Oval; rose-like. Diameter: About 4 cm to 5 cm. Depth: About 1 cm. Flower buds.—Shape: Ovate. Length: About 1 cm to 1.5 cm. Diameter: About 2 cm. Color: Close to 54B. Tepals.—Arrangement: Rosette. Quantity: About 10 to 15 per flower. Length: About 2 cm to 3 cm. Width: About 3 cm to 4 cm. Shape: Obovate to rounded. Apex: Rounded, obtuse. Base: Cordate. Margin: Emarginate, frilled appearance. Texture, upper and lower surfaces: Smooth, glabrous; satiny. Color: When opening and fully opened, upper surface: Close to 54B. When opening and fully opened, lower surface: Close to 54B. Flower bracts.—Quantity/arrangement: Two, opposite. Shape: Broadly ovate. Apex: Obtuse. Margin: Entire. Texture, upper and lower surfaces: Smooth, glabrous. Color, upper surface: Close to 144D and at the margins, close to 45C. Color, lower surface: Close to 145B and at the margins, close to 45C. Peduncles: Angle: Erect to about 30° to 45° from vertical. Length: About 4 cm to 5 cm. Diameter: About 3 mm to 4 mm. Strength: Strong. Texture: Smooth, glabrous. Color: Close to 144B. Pedicels.—Angle: About 30° to 45° from the peduncle. Length: About 2 cm to 3 cm. Diameter: About 2 mm to 3 mm. Strength: Strong. Texture: Smooth, glabrous. Color: Reddish green. Reproductive organs.—Stamens: None observed. Pistils: None observed. Seed/fruit.—Seed and fruit production have not been observed. Disease/pest resistance: Resistance to pathogens and pests common to Begonia has not been observed. Temperature tolerance: Plants of the new Begonia have been observed to tolerate temperatures from about 10° C. to about 35° C.